MedWorm.com provides a medical RSS filtering service. Over 6000 RSS medical sources are combined and output via different filters. This feed contains the latest items from the 'General and Comparative Endocrinology' source. Wed, 08 Feb 2012 15:08:57 +0100 http://www.medworm.com/index.php?rid=5663637&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22293575%26dopt%3DAbstract Authors: Roubos EW, Dahmen M, Kozicz T, Xu L Abstract Leptin is a 16-kDa protein mainly produced and secreted by white adipose tissue and informing various brain centers via leptin receptor long and short forms about the amount of fat stored in the body. In this way leptin exerts a plethora of regulatory functions especially related to energy intake and metabolism, one of which is controlling the activity of the hypothalamo-pituitary-adrenal (HPA) stress axis. First, this review deals with the basic properties of leptin's structure and signaling at the organ, cell and molecule level, from lower vertebrates to humans but with emphasis on rodents because these have been investigated in most detail. Then, attention is given to the various interactions of adipose leptin with the HPA-ax... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5663637 Sat, 28 Jan 2012 05:00:00 +0100 5663637 http://www.medworm.com/index.php?rid=5644282&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22285394%26dopt%3DAbstract Authors: Duportets L, Bozzolan F, Abrieux A, Maria A, Gadenne C, Debernard S Abstract In the male moth, Agrotisipsilon, the behavioral response and neuronal sensitivity in the primary olfactory center, the antennal lobe (AL), to sex pheromone increase with age and juvenile hormone (JH) biosynthesis. Although JH has been shown to control this age-dependent plasticity, the underlying signaling pathway remains obscure. In this context, we cloned a full cDNA encoding the Krüppel homolog 1 transcription factor (AipsKr-h1) of A. ipsilon, which was found to be predominantly expressed in ALs, where its amount increased concomitantly with age and sex pheromone responses. Conversely, the expression of AipsKr-h1 protein in the antenna was age-independent. Moreover, the administration of JH i... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5644282 Fri, 20 Jan 2012 05:00:00 +0100 5644282 http://www.medworm.com/index.php?rid=5644281&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22285395%26dopt%3DAbstract Authors: Crossin GT, Phillips RA, Trathan PN, Fox DS, Dawson A, Wynne-Edwards KE, Williams TD Abstract Physiological mechanisms mediating carryover effects, wherein events or activities occurring in one season, habitat, or life-history stage affect important processes in subsequent life-history stages, are largely unknown. The mechanism most commonly invoked to explain carryover effects from migration centres on the acquisition and utilization of resources (e.g. body mass, or individual 'condition'). However, other mechanisms are plausible, e.g. trade-offs reflecting conflict or incompatibility between physiological regulatory systems required for different activities or life-history stages (e.g. migration vs. reproduction). Here we show that in female black-browed albatrosses (Tha... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5644281 Fri, 20 Jan 2012 05:00:00 +0100 5644281 http://www.medworm.com/index.php?rid=5644280&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22285600%26dopt%3DAbstract Authors: Hur SP, Takeuchi Y, Itoh H, Uchimura M, Takahashi K, Kang HC, Lee YD, Kim SJ, Takemura A Abstract Wrasse species exhibit a definite daily rhythm in locomotor activity and bury themselves in the sand at the bottom of the ocean at night. It remains unclear how their behavior in locomotor activity is endogenously regulated. The aim of the present study was to clarify the involvement of melatonin and clock genes (Per1, Per2, Bmal1, and Cry1) in daily and circadian rhythms of the threespot wrasse, Halichoeres trimaculatus, which is a common species in coral reefs. Daily and circadian rhythms in locomotor activity were monitored under conditions of light-dark cycle (LD=12:12), constant light (LL), and darkness (DD). Daily rhythms in locomotor activity were observed under LD and ... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5644280 Fri, 20 Jan 2012 05:00:00 +0100 5644280 http://www.medworm.com/index.php?rid=5644279&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22285601%26dopt%3DAbstract Authors: Tesone AJ, Regueira E, Fabián Canosa L, Ceballos NR Abstract The reduction of A-ring of glucocorticoids to produce 5α-dihydro-derivatives by 5α-reductases has been considered as a pathway of irreversible inactivation. However, 5α-reduced metabolites of corticosterone and testosterone have significant biological activity. In this paper, we investigated whether toad testicular 5α-reductase (5α-Red) is able to transform corticosterone into 5α-dihydrocorticosterone. Furthermore, we studied the role of 5α-reduced metabolite of corticosterone as a glucocorticoid receptor (GR) agonist. The activity of 5α-Red was assayed in subcellular fractions with [(3)H]corticosterone or [(3)H]testosterone as substrate. The enzyme localizes in microsomes and its optimal pH is between 7... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5644279 Fri, 20 Jan 2012 05:00:00 +0100 5644279 http://www.medworm.com/index.php?rid=5627159&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22265816%26dopt%3DAbstract Authors: Vergauwen J, Goerlich VC, Groothuis T, Eens M, Müller W Abstract In many bird species with hatching asynchrony, yolk androgens increase across the laying sequence. This has been hypothesized to represent a compensatory mechanism for disadvantages of later-hatching chicks - via positive effects of yolk androgens on early competitiveness and growth. However, the costs and benefits of this compensatory strategy probably depend on environmental factors determining the survival chances of the chicks such as the food conditions, which should, therefore, influence maternal yolk androgen deposition. We studied the consequences of manipulated food conditions on the expected level of hatching asynchrony in canaries (Serinus canaria) assigning females to either a low (=LQ) or high q... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5627159 Fri, 13 Jan 2012 05:00:00 +0100 5627159 http://www.medworm.com/index.php?rid=5627158&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22266076%26dopt%3DAbstract Authors: Pérez Sirkin DI, Cánepa MM, Fossati M, Fernandino JI, Delgadin T, Canosa LF, Somoza GM, Vissio PG Abstract Growth hormone (GH) is the main pituitary hormone involved in somatic growth. In fish, the neuroendocrine control of GH is multifactorial due to the interaction of multiple inhibitors and stimulators. Melanin-concentrating hormone (MCH) is a cyclic peptide involved in skin color regulation of fish. In addition, MCH has been related to the regulation of food intake in both mammals and fish. There is only one report presenting evidences on the GH release stimulation by MCH in mammals in experiments in vitro, but there are no data on non-mammals. In the present work, we report for the first time the sequence of MCH and GH cDNA in Cichlasoma dimerus, a freshwater South ... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5627158 Wed, 11 Jan 2012 05:00:00 +0100 5627158 http://www.medworm.com/index.php?rid=5607245&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22248444%26dopt%3DAbstract Authors: Searcy BT, Beckstrom-Sternberg SM, Beckstrom-Sternberg JS, Stafford P, Schwendiman AL, Soto-Pena J, Owen MC, Ramirez C, Phillips J, Veldhoen N, Helbing CC, Propper CR Abstract Because thyroid hormones (THs) are conserved modulators of development and physiology, identification of compounds adversely affecting TH signaling is critical to human and wildlife health. Anurans are an established model for studying disruption of TH signaling because metamorphosis is dependent upon the thyroid system. In order to strengthen this model and identify new gene transcript biomarkers for TH disruption, we performed DNA microarray analysis of Xenopus laevis tadpole tail transcriptomes following treatment with triiodothyronine (T(3)). Comparison of these results with previous studies in f... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5607245 Wed, 11 Jan 2012 05:00:00 +0100 5607245 http://www.medworm.com/index.php?rid=5607247&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22248442%26dopt%3DAbstract Authors: Adkins-Regan E Abstract Comparative endocrinology is a fascinating field of science in part because it addresses both ultimate and proximate causation. Research on sexual dimorphism and sexual differentiation has excellent potential for this kind of integration. Vertebrate comparative endocrinologists have made many important discoveries about the role of genes and sex steroid hormones in the organization and activation of sexually differentiated behavior, brain function, anatomy and physiology. In addition to taxonomically general principles and conserved features, there is also striking diversity in sexual differentiation processes. Much of the evolutionary basis of this diversity (its phylogenetic history and adaptive functions) is not well understood. A set of question... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5607247 Tue, 10 Jan 2012 05:00:00 +0100 5607247 http://www.medworm.com/index.php?rid=5607246&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22248443%26dopt%3DAbstract Authors: Jenks BG, Kuribara M, Kidane AH, Kramer BM, Roubos EW, Scheenen WJ Abstract Brain-derived neurotrophic factor (BDNF) is, despite its name, also found outside the central nervous system (CNS), but the functional significance of this observation is largely unknown. This review concerns the expression of BDNF in the pituitary gland. While the presence of the neurotrophin in the mammalian pituitary gland is well documented its functional significance remains obscure. Studies on the pars intermedia of the pituitary of the amphibian Xenopus laevis has shown that BDNF is produced by the neuroendocrine melanotrope cells, its expression is physiologically regulated, and the melanotrope cells themselves express receptors for the neurotrophin. The neurotrophin has been shown to act a... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5607246 Tue, 10 Jan 2012 05:00:00 +0100 5607246 http://www.medworm.com/index.php?rid=5607244&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22251656%26dopt%3DAbstract In conclusion, the conceptus viability and growth appear to be strongly related to maternal metabolic features and, thus, affected in females with alterations in lipid metabolism. PMID: 22251656 [PubMed - as supplied by publisher] (Source: General and Comparative Endocrinology) General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5607244 Tue, 10 Jan 2012 05:00:00 +0100 5607244 http://www.medworm.com/index.php?rid=5607249&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22245290%26dopt%3DAbstract Authors: Wang C, Zhang J, Tobe SS, Bendena WG Abstract The larval ring gland and adult corpus allatum (CA) of Drosophilamelanogaster produce at least three sesquiterpenoid products: methyl farnesoate (MF), juvenile hormone III (JHIII), and JHIII bisepoxide (JHB(3)). Our understanding of neuropeptide regulation of sesquiterpenoid biosynthesis in D. melanogaster has been hampered by uncertainty over the biosynthetic pathway and the sites of action of regulators. As an approach to defining the neuropeptide regulators, we have used invivo gene-specific silencing (RNAi). D. melanogaster strains containing an inducible UAS-RNAi construct made to either PheGlyLeu-NH(2)-allatostatin (FGLa/AST) and its cognate receptors Dar-1 and Dar-2 or PISCF-allatostatin (PISCF/AST) or its cognate recept... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5607249 Sun, 08 Jan 2012 05:00:00 +0100 5607249 http://www.medworm.com/index.php?rid=5607248&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22245291%26dopt%3DAbstract Authors: Ito M, Tamura K, Mawaribuchi S, Takamatsu N Abstract The tumor necrosis factor (TNF) superfamily includes death receptor (DR) ligands, such as TNF-α, FasL, and TRAIL. Death receptors (DRs) induce intracellular signaling upon engagement of their cognate DR ligands, either leading to apoptosis, survival, or proinflammatory responses. The DR signaling is mediated by the recruitment of several death domain (DD)-containing molecules such as Fas-associated death domain (FADD) and receptor-interacting protein (RIP) 1. In this review, we describe DR signaling in mammals, and describe recent findings of DR signaling during metamorphosis in the African clawed frog Xenopus laevis. Specifically, we focus on the cell fate (apoptosis or survival) mediated through a DR ligand, TNF-α or... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5607248 Sun, 08 Jan 2012 05:00:00 +0100 5607248 http://www.medworm.com/index.php?rid=5607252&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22245261%26dopt%3DAbstract Authors: Clapp C, Escalera LM, Escalera GM Abstract The hormone prolactin (PRL), fundamental for lactation in mammals, is known to exert a wide diversity of actions in the various vertebrate groups. Blood vessels are surfacing as important PRL targets, contributing to these hormonal functions. PRL promotes the growth of new blood vessels (angiogenesis) and is proteolytically cleaved to vasoinhibins, a family of peptides (including 16-kDa PRL) with potent antiangiogenic and blood vessel regression effects. These opposing actions point to the regulation of the proteases responsible for PRL cleavage as an efficient way to balance blood vessel growth and involution. This review briefly summarizes the effects of PRL and vasoinhibins on blood vessels in mammals and discusses whether simi... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5607252 Thu, 05 Jan 2012 05:00:00 +0100 5607252 http://www.medworm.com/index.php?rid=5607251&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22245262%26dopt%3DAbstract Authors: Eisthen HL, Krause BC Abstract Axolotls (Ambystoma mexicanum) are aquatic salamanders that are widely used in research. Axolotls have been bred in laboratories for nearly 150years, yet little is known about the basic biology of reproduction in these animals. We investigated the effects of changing day length, time of year, and food availability on levels of circulating estradiol and androgens in adult female and male axolotls, respectively. In addition, we examined the effects of these variables on the mass of ovaries, oviducts, and eggs in females and on mass of testes in males relative to each individual's body weight, to calculate a form of gonadosomatic index (GSI). In both sexes, GSI was not correlated with levels of circulating steroids. In female axolotls, estradiol... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5607251 Thu, 05 Jan 2012 05:00:00 +0100 5607251 http://www.medworm.com/index.php?rid=5607250&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22245263%26dopt%3DAbstract We examined the effects of diet and photoperiod on reproduction in female California mice. Mice placed on either short days (8L:16D) or long days (16L:8D) were food restricted (80% of normal intake) or fed ad libitum. Short day-food restricted mice showed significant regression of the reproductive system. GnRH-immunoreactivity was increased in the tuberal hypothalamus of long day-food restricted mice. This may be associated with the sparing effect long days have when mice are food restricted. The number of GFAP-immunoreactive fibers in proximity to GnRH nerve terminals correlated negatively with uterine size in ad libitum but not food restricted mice, suggesting diet may alter glial regulation of the reproductive axis. There was a trend towards food restriction increasing uterine expressio... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5607250 Thu, 05 Jan 2012 05:00:00 +0100 5607250 http://www.medworm.com/index.php?rid=5607253&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22240277%26dopt%3DAbstract In this study, we investigated the effects of zebrafish BMP2b (zfBmp2b) and BMP4 (zfBmp4) on the expression of fshr and lhcgr using a novel co-culture approach. The recombinant zfBmp2b or zfBmp4-producing CHO cells were co-cultured with the zebrafish follicle cells followed by real-time qPCR analysis of fshr and lhcgr expression. Our results showed that zfBmp2b and zfBmp4 both down-regulated fshr, while up-regulated lhcgr expression at 24h of co-culturing. This finding, together with the high expression level of BMP receptors in the follicle cells prior to oocyte maturation, strongly suggests a potential role for BMPs in the differential expression of fshr and lhcgr, especially in the full-grown follicles before maturation. As BMPs are largely expressed in the oocyte, this also implies an ... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5607253 Tue, 03 Jan 2012 05:00:00 +0100 5607253 http://www.medworm.com/index.php?rid=5580270&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22233772%26dopt%3DAbstract Authors: Alderman SL, McGuire A, Bernier NJ, Vijayan MM Abstract Cortisol, the primary circulating corticosteroid in teleosts, is elevated during stress following activation of the hypothalamus-pituitary-interrenal (HPI) axis. Cortisol exerts genomic effects on target tissues in part by activating glucocorticoid receptors (GR). Despite a well-established negative feedback loop involved in plasma cortisol regulation, the role of GR in the functioning of the HPI axis during stress in fish is still unclear. We used mifepristone (a GR antagonist) to suppress GR signaling in rainbow trout (Oncorhynchus mykiss) and assessed the resultant changes to HPI axis activity. We show for the first time that mifepristone caused a functional knockdown of GR by depleting protein expression 40-75%. T... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5580270 Tue, 03 Jan 2012 05:00:00 +0100 5580270 http://www.medworm.com/index.php?rid=5580269&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22233773%26dopt%3DAbstract Authors: Dupont J, Métayer-Coustard S, Ji B, Ramé C, Gespach C, Voy B, Simon J Abstract The role of insulin in chicken adipose tissue appears weak or questionable. In a first study, proximal and distal components of the insulin signaling cascade were characterized in abdominal adipose tissue of fasted or fed chickens for the first time. Similar measurements were performed on epididymal adipose tissue from fasted or fed rats for comparison. Tyrosine phosphorylation of IR beta subunit, IRS-1 and Shc and phosphorylation of downstream components (Akt and MAPK ERK1/2) were significantly reduced as expected by fasting in rat, but not in chicken. Phosphorylation of MAPK P38 was increased by fasting in chicken but not in rat. Phosphorylation of AMPK was not affected in the conditions inv... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5580269 Tue, 03 Jan 2012 05:00:00 +0100 5580269 http://www.medworm.com/index.php?rid=5580268&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22233774%26dopt%3DAbstract In conclusion, ovariectomized mice demonstrate a different body weight and leukocyte response to short-term estrogen treatment than that of ovariectomized rats, and short-term estrogen treatment modulates leukocyte phenotype. These data broaden our understanding of estrogen's effects on body weight and leukocyte infiltration, and may aid in increasing our understanding of how males and females differ in response to acute muscle injury. PMID: 22233774 [PubMed - as supplied by publisher] (Source: General and Comparative Endocrinology) General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5580268 Tue, 03 Jan 2012 05:00:00 +0100 5580268 http://www.medworm.com/index.php?rid=5580272&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22227219%26dopt%3DAbstract In conclusion, the immunoassay developed has proven to be sensitive, specific and accurate for measuring European sea bass FSH, and it represents a valuable tool for future studies on the reproductive endocrinology of this species. PMID: 22227219 [PubMed - as supplied by publisher] (Source: General and Comparative Endocrinology) General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5580272 Mon, 02 Jan 2012 05:00:00 +0100 5580272 http://www.medworm.com/index.php?rid=5580271&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22230767%26dopt%3DAbstract Authors: Hews DK, Hara E, Anderson MC Abstract We studied neuroendocrine correlates of aggression differences in adults of two Sceloporus lizard species. These species differ in the degree of sex difference in aggressive color signals (belly patches) and in aggression: Sceloporus undulatus (males blue, high aggression; females white, low aggression) and Sceloporus virgatus (both sexes white, lower aggression). We measured plasma testosterone and counted cells expressing androgen receptor-like immunoreactivity to the affinity-purified polyclonal AR antibody, PG-21, in three brain regions of breeding season adults. Male S. undulatus had the highest mean plasma testosterone and differed significantly from conspecific females. In contrast, there was no sex difference in plasma testoste... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5580271 Mon, 02 Jan 2012 05:00:00 +0100 5580271 http://www.medworm.com/index.php?rid=5580278&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22226730%26dopt%3DAbstract Authors: Cánepa MM, Zhu Y, Fossati M, Stiller JW, Vissio PG Abstract Somatolactin (SL) and SL receptor (SLR) belong to the growth hormone and cytokine type I receptor superfamilies, respectively. However, further research is required to define the duplications and functions of SL and its receptors in basal vertebrates including environmental background color adaptation in fish. In the present study, we cloned and sequenced SL and its putative receptor (SLR), classified and compared the sequences phylogenetically, and determined SL and SLR mRNA expression levels during long-term background color exposure in Cichlasoma dimerus, a freshwater South American cichlid. Our results show that C. dimerus SL and SLR share high sequence similarity with homologous from other perciform fish. Ph... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5580278 Thu, 29 Dec 2011 05:00:00 +0100 5580278 http://www.medworm.com/index.php?rid=5580277&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22226731%26dopt%3DAbstract Authors: Applebaum SL, Finn RN, Faulk CK, Joan Holt G, Scott Nunez B Abstract Interactions between the thyroid hormone (TH) and corticosteroid (CS) hormone axes are suggested to regulate developmental processes in vertebrates with a larval phase. To investigate this hypothesis, we isolated three nuclear receptors from a larval acanthomorph teleost, the red drum (Sciaenops ocellatus), and established their orthologies as thraa, thrb-L and gra-L using phylogenomic and functional analyses. Functional characterization of the TH receptors in COS-1 cells revealed that Thraa and Thrb-L exhibit dose-dependent transactivation of a luciferase reporter in response to T3, while SoThraa is constitutively active at a low level in the absence of ligand. To test whether interactions between the TH... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5580277 Wed, 28 Dec 2011 05:00:00 +0100 5580277 http://www.medworm.com/index.php?rid=5580276&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22226757%26dopt%3DAbstract Authors: Paluzzi JP Abstract Insects have adapted to live in a wide variety of habitats and utilize an array of feeding strategies that present challenges to their ability to maintain osmotic balance. Regardless of the feeding strategy, water and ion levels within the haemolymph (insect blood) are maintained within a narrow range. This homeostasis involves the action of a variety of tissues, but is often chiefly regulated by the excretory system. Until recently, most research on the hormonal control of the excretory tissues has focused on factors known to have diuretic activities. In this mini-review, the current state of knowledge on anti-diuretic factors in insects will be discussed with a particular emphasis on the CAPA peptides in the blood-feeding Chagas' disease vector, Rhodn... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5580276 Wed, 28 Dec 2011 05:00:00 +0100 5580276 http://www.medworm.com/index.php?rid=5580274&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22226759%26dopt%3DAbstract This study suggests that invasive species may impose physiological stress on native vertebrates, but that the consequences of this stress may be complicated and unpredictable. PMID: 22226759 [PubMed - as supplied by publisher] (Source: General and Comparative Endocrinology) General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5580274 Wed, 28 Dec 2011 05:00:00 +0100 5580274 http://www.medworm.com/index.php?rid=5580273&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22226760%26dopt%3DAbstract In this study, we investigated the presence of nerve growth factor (NGF) and its receptors tyrosine kinase A (TrkA) and p75 in the uterus of the wild ground squirrels during the estrous period, early pregnancy and non-breeding period. In the estrous period and early pregnancy, NGF and TrkA were immunolocalized in stromal cells, luminal epithelial cells, glandular cells and smooth muscle cells whereas in the non-breeding period, both of them were detected only in luminal epithelial cells and glandular cells, but not in stromal cells or smooth muscle cells. Stronger immunostaining of NGF and TrkA was observed in luminal epithelial cells and glandular cells in the estrous period and early pregnancy as compared to the non-breeding period. p75 was immunolocalized only in luminal epithelial and ... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5580273 Wed, 28 Dec 2011 05:00:00 +0100 5580273 http://www.medworm.com/index.php?rid=5580279&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22222933%26dopt%3DAbstract Authors: Caro SP Abstract Seasonal timing is studied by ecologists and physiologists alike and it is now widely recognized that further integration of these fields is needed for a full understanding of phenology. This is especially true in the light of the impact of global climate change on living organisms. In studies of avian reproduction, one obstacle to this integration is that ecologists and physiologists do not allocate their research efforts equally to males and females. The physiological orchestration of breeding stages has been studied almost exclusively in males, while in avian ecology and evolutionary biology females are more often considered. This sex bias has severe implications: sexes differ in the way they use external cues to organize their life cycles, but often cu... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5580279 Tue, 27 Dec 2011 05:00:00 +0100 5580279 http://www.medworm.com/index.php?rid=5580275&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22226758%26dopt%3DAbstract Authors: Hoskins LJ, Volkoff H Abstract Studying the endocrine regulation of food intake in fish can be challenging due to the diversity in appetite-regulating hormones and the diversity within the fish group itself. Studies show that although the structure of the hormones is relatively conserved among vertebrates, their functions might vary between fish and mammals as well as among fish species. In addition, feeding behavior and the action of appetite regulators can be largely modulated by the feeding and reproductive status of the fish as well as the environment in which they evolve. This review gives a brief perspective of the endocrine regulation of feeding in fish, some of the methods used, and challenges encountered when using a comparative approach. PMID: 22226758 [PubMe... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5580275 Tue, 27 Dec 2011 05:00:00 +0100 5580275 http://www.medworm.com/index.php?rid=5568752&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22212825%26dopt%3DAbstract This study examines the relationship between natural variation in gestational cortisol and fetal and postnatal growth in marmoset monkeys. Urinary samples obtained during the mother's gestation were analyzed for cortisol. Marmoset body mass index (BMI) was measured from birth through 540days in 30- or 60-day intervals. Multi-level modeling was used to test if marmoset growth over time was predicted by changes in gestational cortisol controlling for time, sex, litter, and litter size. The results show that offspring exposed to intra-uterine environments with elevated levels of cortisol had lower linear BMI rates of change shortly after birth than did offspring exposed to lower levels of cortisol, but exhibited a higher curvilinear growth rate during adolescence. Average daily change in gest... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5568752 Mon, 26 Dec 2011 05:00:00 +0100 5568752 http://www.medworm.com/index.php?rid=5568751&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22214654%26dopt%3DAbstract Authors: Lorenzi V, Grober MS Abstract The neurotransmitter serotonin (5-HT) may play a central role in the inhibition of socially regulated sex change in fish because of its known modulation of both aggressive and reproductive behavior. This is the first study to use immunohistochemical techniques to examine the morphometry of serotonergic neurons at different times during sex change. Using a model species wherein sex change is socially regulated via agonistic social interactions (the bluebanded goby, Lythrypnus dalli), we sampled brains of males and females with different social status, and of females at different times during sex change. Consistent with previous studies on other teleosts, immunoreactive neurons were found in the posterior periventricular nucleus (NPPv), the nucl... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5568751 Mon, 26 Dec 2011 05:00:00 +0100 5568751 http://www.medworm.com/index.php?rid=5568756&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22210163%26dopt%3DAbstract Authors: Lutterschmidt DI Abstract The majority of studies on reproductive neuroendocrinology in snakes have focused on one particular snake population in Manitoba, Canada, the red-sided garter snake (Thamnophis sirtalis parietalis). Although traditionally these studies have emphasized its unusual temporal dissociation between mating behavior and peak gonadal activity, current evidence suggests that reproductive regulation in this population may be more similar to the norm than previously thought. Like other ectotherms, temperature plays a critical role in activating reproductive behavior in red-sided garter snakes. Diel melatonin and corticosterone rhythms appear to be important in transducing temperature cues, and it is clear that both hormones regulate courtship behavior during ... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5568756 Thu, 22 Dec 2011 05:00:00 +0100 5568756 http://www.medworm.com/index.php?rid=5568755&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22210245%26dopt%3DAbstract Authors: Komorowski LK, Lecaude SG, Westring CG, Danielson PB, Dores RM Abstract Analyses of prodynorphin and proenkephalin cDNAs cloned from the central nervous system of the shark, Heterodontus portusjacksoni, provided additional evidence that these two opioid precursor-coding genes were most likely directly derived from a common ancestral gene. The two cDNAs could be aligned by inserting only seven gaps. The prodynorphin cDNA encodes five opioid sequences which could be aligned to opioid positions B through F in the proenkephalin cDNA. The sequence identity within the opioid positions was 59% at the amino acid level. Shark α-neo-endorphin, dynorphin A, and dynorphin B have amino acid motifs in common with shark met-enkephalin-8, and shark proenkephalin opioid positions E and F,... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5568755 Thu, 22 Dec 2011 05:00:00 +0100 5568755 http://www.medworm.com/index.php?rid=5568754&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22210246%26dopt%3DAbstract In this study, we examine the metabolism of [(3)H]-progesterone injected into freshly laid European starling eggs throughout the first 5days of development by characterization of radioactivity within the egg homogenate. We also introduce a technique that utilizes a focal, freeze/thaw cycle to prevent embryonic development and allows us to assess the role of the embryo in metabolizing progesterone during early incubation. Two major findings result. First is that [(3)H]-progesterone is metabolized in eggs possessing a developing embryo, but not in eggs with disrupted embryonic development. Second is that the change in the distribution of radioactivity within eggs possessing an embryo is the result of metabolism of [(3)H]-progesterone to a more polar form that is subsequently conjugated. Toge... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5568754 Thu, 22 Dec 2011 05:00:00 +0100 5568754 http://www.medworm.com/index.php?rid=5568753&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22210247%26dopt%3DAbstract Authors: Charfeddine IB, Riepe FG, Kahloul N, Kulle AE, Adala L, Mamaï O, Amara A, Mili A, Amri F, Saad A, Holterhus PM, Gribaa M Abstract Steroid 11β hydroxylase deficiency (11β-OHD) (OMIM # 202010) is the second most common form of congenital adrenal hyperplasia (CAH), accounting for 5-8% of all cases. It is an autosomal recessive enzyme defect impairing the biosynthesis of cortisol. The CYP11B1 gene encoding this enzyme is located on chromosome 8q22, approximately 40kb from the highly homologous CYP11B2 gene encoding for the aldosterone synthase. Virilization and hypertension are the main clinical characteristics of this disease. In Tunisia, the incidence of 11β-OHD appears higher due to a high rate of consanguinity (17.5% of congenital adrenal hyperplasia). The identical pr... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5568753 Thu, 22 Dec 2011 05:00:00 +0100 5568753 http://www.medworm.com/index.php?rid=5552912&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22202604%26dopt%3DAbstract In this study, we used rainbow trout (Oncorhynchus mykiss) to identify the cellular mechanisms involved with this metabolic shift. Fish were placed on one of five dietary regimes - fed continuously for 2 or 4weeks, fasted continuously for 2 or 4weeks, or fasted 2weeks then refed 2weeks - and the effects on organismal growth and lipid catabolism and on the activation state of signaling elements (e.g., Akt, ERK, JAK-STAT, PKC) in selected tissues were measured. Fasting for either 2 or 4weeks significantly retarded growth in terms of body weight, body length, and body condition; refeeding restored growth such that body length and body condition were similar to measures seen in continuously fed fish. Fasting activated lipid catabolism by stimulating the mRNA expression and catalytic activity o... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5552912 Tue, 20 Dec 2011 05:00:00 +0100 5552912 http://www.medworm.com/index.php?rid=5552917&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22202599%26dopt%3DAbstract Authors: Chourasia TK, Joy KP Abstract Ovarian pieces containing postvitellogenic follicles were incubated in vitro with different concentrations of the catecholestrogen 2-hydroxyestradiol-17β (2-OHE(2)) to evaluate its effects on steroid production and germinal vesicle breakdown (GVBD) in the catfish Heteropneustes fossilis. The incubation with 2-OHE(2) induced a shift in steroidogenic pattern: the C(19) and C(18) steroids testosterone (T) and estradiol-17β (E(2)), respectively were significantly decreased with a concomitant significant increase in the C(21) steroids progesterone (P(4)), 17-hydroxyprogesterone (17-OHP), 17,20β-dihydroxy-4-pregnen-3-one (17,20β-DP), 17,20β-dihydroxy-4-pregnen-3-one (17,20α-DP) and cortisol (F). Concomitantly, the catecholestrogen induced dose... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5552917 Mon, 19 Dec 2011 05:00:00 +0100 5552917 http://www.medworm.com/index.php?rid=5552916&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22202600%26dopt%3DAbstract Authors: Jouaux A, Heude-Berthelin C, Sourdaine P, Blin JL, Mathieu M, Kellner K Abstract Insulin pathways were demonstrated from invertebrates to vertebrates to be involved in the regulation of numerous processes including storage metabolism and reproduction. In addition, insulin system may integrate variations of environmental conditions like dietary restrictions. In the Pacific oyster Crassostrea gigas, reproductive and storage compartments are closely intricated in the gonadal area and their respective development was found to be dependant of trophic conditions. For these reasons, C. gigas is an original and interesting model for investigating the role of insulin control in the balance between storage and reproduction and the integration of environmental parameters. On the basi... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5552916 Mon, 19 Dec 2011 05:00:00 +0100 5552916 http://www.medworm.com/index.php?rid=5552915&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22202601%26dopt%3DAbstract Authors: Schöpper H, Palme R, Ruf T, Huber S Abstract Prenatal stress can alter hypothalamic-pituitary-adrenal axis function with potential consequences for later life. The aim of our study was to examine in guinea pigs (Cavia aperea f. porcellus) the effects of stress experienced during F0 pregnancy on glucocorticoid levels in plasma and feces, as well as challenge performance, in F1 offspring (n=44) and fecal glucocorticoid levels in F2 offspring (n=67). F1 animals were either born to F0 dams that had been stressed with strobe light during early to mid pregnancy, resulting in a short term increase but long-term down-regulation of maternal glucocorticoid levels, or to undisturbed F0 dams. The same stressor was used as a challenge for F1 offspring at age 26days and around 100days.... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5552915 Mon, 19 Dec 2011 05:00:00 +0100 5552915 http://www.medworm.com/index.php?rid=5552914&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22202602%26dopt%3DAbstract Authors: Wade J Abstract Morphology parallels function on a variety of levels in reproductive circuits in anole lizards, as in many vertebrate groups. For example, across species within the anole genus the muscle fibers regulating extension of a throat fan used in courtship are larger in males than females. Endocrine factors controlling behavior and morphology have been studied in detail in one species, the green anole (Anolis carolinensis). This review briefly describes the results that have been obtained and highlights key areas for future investigation that will provide insights on mechanisms from a comparative perspective. PMID: 22202602 [PubMed - as supplied by publisher] (Source: General and Comparative Endocrinology) General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5552914 Mon, 19 Dec 2011 05:00:00 +0100 5552914 http://www.medworm.com/index.php?rid=5552913&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22202603%26dopt%3DAbstract Authors: Baugh AT, Schaper SV, Hau M, Cockrem JF, de Goede P, Oers KV Abstract Animal 'personality' describes consistent individual differences in suites of behaviors, a phenomenon exhibited in diverse animal taxa and shown to be under natural and sexual selection. It has been suggested that variation in personality reflects underlying physiological variation; however there is limited empirical evidence to test this hypothesis in wild animals. The hypothalamic-pituitary-adrenal axis is hypothesized to play a central role in personality variation. Here we tested whether in great tits Parus major variation in personality traits is related to plasma concentrations of corticosterone (CORT). Using a capture-restraint protocol we examined baseline and stress-induced CORT levels in two ca... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5552913 Mon, 19 Dec 2011 05:00:00 +0100 5552913 http://www.medworm.com/index.php?rid=5552911&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22202605%26dopt%3DAbstract Authors: Martyniuk CJ, Popesku JT, Chown B, Denslow ND, Trudeau VL Abstract Neuroendocrine systems integrate both extrinsic and intrinsic signals to regulate virtually all aspects of an animal's physiology. In aquatic toxicology, studies have shown that pollutants are capable of disrupting the neuroendocrine system of teleost fish, and many chemicals found in the environment can also have a neurotoxic mode of action. Omics approaches are now used to better understand cell signaling cascades underlying fish neurophysiology and the control of pituitary hormone release, in addition to identifying adverse effects of pollutants in the teleostean central nervous system. For example, both high throughput genomics and proteomic investigations of molecular signaling cascades for both neurot... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5552911 Mon, 19 Dec 2011 05:00:00 +0100 5552911 http://www.medworm.com/index.php?rid=5552910&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22202606%26dopt%3DAbstract Authors: Yoshihara C, Fukao A, Ando K, Tashiro Y, Taniuchi S, Takahashi S, Takeuchi S Abstract Hair and feather pigmentation is mainly determined by the distribution of two kinds of melanin, eumelanin and pheomelanin, which produce brown to black and yellow to red colorations, respectively. The agouti signaling protein (ASIP) acts as an antagonist or an inverse agonist of the melanocortin 1 receptor (MC1R), a G protein-coupled receptor for α-melanocyte-stimulating hormone (α-MSH). This antagonism of the MC1R by ASIP on melanocytes initiates a switch of melanin synthesis from eumelanogenesis to pheomelanogenesis in mammals. In the present study, we isolated multiple ASIP mRNA variants generated by alternative splicing and promoters in chicken feather follicles. The mRNA variants s... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5552910 Mon, 19 Dec 2011 05:00:00 +0100 5552910 http://www.medworm.com/index.php?rid=5552922&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22197207%26dopt%3DAbstract Authors: Zhang W, Lu H, Jiang H, Li M, Zhang S, Liu Q, Zhang L Abstract Aromatase (CYP19A1) catalyzes the conversion of androgens to estrogens. In teleosts, duplicated copies of cyp19a1 genes, namely cyp19a1a and cyp19a1b, were identified, however, the transcriptional regulation of these two genes remains poorly understood. In the present study, the 5'-flanking regions of the orange-spotted grouper cyp19a1a (gcyp19a1a) and cyp19a1b (gcyp19a1b) genes were isolated and characterized. The proximal promoter regions of both genes were relatively conserved when compared to those of the other teleosts. Notably, a conserved FOXO transcriptional factor binding site was firstly reported in the proximal promoter of gcyp19a1a, and deletion of the region (-112 to -60) containing this site signi... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5552922 Wed, 14 Dec 2011 05:00:00 +0100 5552922 http://www.medworm.com/index.php?rid=5552921&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22197208%26dopt%3DAbstract Authors: Kobayashi Y, Mizusawa K, Chiba H, Tagawa M, Takahashi A Abstract Our previous studies showed that in barfin flounder, α-melanocyte-stimulating hormone (α-MSH) stimulates pigment dispersion in xanthophores, while it shows negligible effects in melanophores. The present study was undertaken to evaluate whether these results are limited to barfin flounder by using Japanese flounder. Three subtypes of proopiomelanocortin gene encoding melanocortins (MCs) were expressed in the Japanese flounder pituitary, one of which was also expressed in the skin. Expression of melanocortin 5 receptor gene (Mc5r) was observed in isolated xanthophores, while that of Mc1r and Mc5r was found in melanophores. In the xanthophores of Japanese flounder skin, α-MSH as well as desacetyl (Des-Ac)-α... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5552921 Wed, 14 Dec 2011 05:00:00 +0100 5552921 http://www.medworm.com/index.php?rid=5552920&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22197209%26dopt%3DAbstract We examined whether these techniques could provide this much needed information for a largely monomorphic anuran with an unconfirmed mating season in the wild. We analysed urinary estrone conjugate, testosterone, and progesterone metabolites to infer the time of breeding and to identify sex in the endangered Maud Island frog, Leiopelma pakeka. Testosterone metabolites in males and estrone and progesterone metabolites in females were at their peak during winter for both wild and captive frogs. These urinary metabolite patterns were consistent with the high proportion of females exhibiting enlarged ovarian follicles in winter months. Sex identification based on urinary estrone metabolite levels was 94% correct in this largely monomorphic species, in which the sexes overlap in snout-to-vent l... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5552920 Wed, 14 Dec 2011 05:00:00 +0100 5552920 http://www.medworm.com/index.php?rid=5552919&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22197210%26dopt%3DAbstract Authors: Zi XD, Chen DW, Wang HM Abstract Prolactin (PRL) plays central roles in a wide range of body functions in mammals, and the actions are mediated by the specific cell surface receptor, the prolactin receptor (PRLR). To better understand the role of PRL in the yak (Bos grunniens), in the present study, we first cloned yak PRLR cDNA, and compared its mRNA expression in several tissues with cattle (Bos taurus). By reverse transcriptase-polymerase chain reaction (RT-PCR) strategy, we obtained full-length of yak PRLR cDNA sequence comprised of an open reading frame of 1746bp encoding a 581 amino acid protein, and contained a signal sequence and a transmembrane region. The intracellular domain had two pairs of cysteine residues and a WSXWS motif. The cytoplasmic domain comprised 3... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5552919 Wed, 14 Dec 2011 05:00:00 +0100 5552919 http://www.medworm.com/index.php?rid=5552918&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22197211%26dopt%3DAbstract Authors: Hopkins PM Abstract To help celebrate the 50th anniversary of General and Comparative Endocrinology, the history of only a small portion of crustacean endocrinology is presented here. The field of crustacean endocrinology dates back to the decades prior to the establishment of General and Comparative Endocrinology and the first article about crustacean endocrinology published in this journal [77] was concerned with the anatomy of neurosecretory and neurohemal structures in brachyuran crabs. This review looks at the history of neuroendocrinology in crustaceans during that time and tries to put perspective on the future of this field. PMID: 22197211 [PubMed - as supplied by publisher] (Source: General and Comparative Endocrinology) General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5552918 Wed, 14 Dec 2011 05:00:00 +0100 5552918 http://www.medworm.com/index.php?rid=5538882&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22172340%26dopt%3DAbstract In this study, we have characterized the role of insulin in chick myoblast proliferation and differentiation in vitro and in vivo, and have revealed novel details of how this exogenous hormone influences myogenic genes during differentiation. Chick myoblast cells cultured in differentiation medium (DMEM containing 2% FBS) supplemented with insulin exhibited a significant decrease in MyoD and myogenin mRNA expression after 12h of culture compared to cells cultured in differentiation media alone. MyoD and myogenin immunoreactive proteins in cells cultured in differentiation medium supplemented with insulin were quite low compared to those in control culture. Supplementation of the differentiation media containing insulin with LY294002 (a PI3K inhibitor) induced myoblast differentiation. A si... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5538882 Thu, 08 Dec 2011 05:00:00 +0100 5538882 http://www.medworm.com/index.php?rid=5538881&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22172341%26dopt%3DAbstract In this study, we examine plasma testosterone (T), 11-ketotestosterone (11-KT) and maturation-inducing steroid (MIS; 17α,20β-dihydroxy-4-pregnen-3-one) profiles of spawning hooknoses and jacks. Furthermore, we examine relationships between androgens and primary (gonad mass, gonadosomatic index and sperm traits) and secondary (total mass, body size, hump depth and kype length) sexual characters. Relationships between MIS and sperm traits are also examined. We found that hooknoses and jacks did not significantly differ in terms of plasma T, 11-KT or MIS concentrations. Moreover, we found significant positive relationships between levels of both androgens within each ART. There were no significant relationships between androgens, MIS and sperm traits. T and 11-KT concentrations co-varied po... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5538881 Thu, 08 Dec 2011 05:00:00 +0100 5538881 http://www.medworm.com/index.php?rid=5538880&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22172342%26dopt%3DAbstract Authors: Sun B, Kavanaugh SI, Tsai PS Abstract Several protostomian molecules that structurally resemble chordate gonadotropin-releasing hormone (GnRH) have been identified through cloning, biochemical purification or data mining. These molecules share considerable sequence and structural similarities with chordate GnRH, leading to the current belief that protostomian and chordate forms of GnRH share a common ancestor. However, the physiological significance of these protostomian GnRH-like molecules remains poorly understood. This knowledge gap hampers our understanding of how GnRH has evolved functionally over time. This review provides a summary of our recent functional characterization of a GnRH-like molecule (ap-GnRH) in a gastropod mollusk, Aplysia californica, and presents pr... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5538880 Thu, 08 Dec 2011 05:00:00 +0100 5538880 http://www.medworm.com/index.php?rid=5538879&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22178432%26dopt%3DAbstract Authors: Palacios MG, Sparkman AM, Bronikowski AM Abstract Glucocorticoids are main candidates for mediating life-history trade-offs by regulating the balance between current reproduction and survival. It has been proposed that slow-living organisms should show higher stress-induced glucocorticoid levels that favor self-maintenance rather than current reproduction when compared to fast-living organisms. We tested this hypothesis in replicate populations of two ecotypes of the garter snake (Thamnophis elegans) that exhibit slow and fast pace of life strategies. We subjected free-ranging snakes to a capture-restraint protocol and compared the stress-induced corticosterone levels between slow- and fast-living snakes. We also used a five-year dataset to assess whether baseline corticos... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5538879 Thu, 08 Dec 2011 05:00:00 +0100 5538879 http://www.medworm.com/index.php?rid=5538884&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22166814%26dopt%3DAbstract Authors: Xu L, Scheenen WJ, Roubos EW, Kozicz T Abstract The continuously changing environment demands for adequate stress responses to maintain the internal dynamic equilibrium of body and mind. A successful stress response requires energy, in an amount matching the severity of the stressor and the type of response ('fight, flight or freeze'). The stress response is generated by the central nervous system, which needs to be informed about both the threatening stressor and the availability of energy. In this review, evidence is considered for a role of the midbrain Edinger-Westphal centrally projecting neuron population (EWcp; synonym: non-preganglionic Edinger-Westphal nucleus) in the energy-dependent stress adaptation response. It deals with studies on the neurochemical organizat... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5538884 Wed, 07 Dec 2011 05:00:00 +0100 5538884 http://www.medworm.com/index.php?rid=5538883&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22166815%26dopt%3DAbstract Authors: Shimizu Y, Tomikawa J, Hirano K, Nanikawa Y, Akazome Y, Kanda S, Kazeto Y, Okuzawa K, Uenoyama Y, Ohkura S, Tsukamura H, Maeda KI, Gen K, Oka Y, Yamamoto N Abstract kisspeptins that are encoded by kiss1 gene are now considered the key regulator of reproduction from a number of studies in mammals. In most vertebrates, a paralogue of kiss1, called kiss2, is also present, and the functional significance of kisspeptins is not known precisely. In the present study, we have cloned kiss2 from a perciform teleost, the red seabream Pagrus major. The amino acid sequence deduced from the red seabream kiss2 contained a highly conserved 10-amino-acid residue, Kiss2(10) or kp-10. A kiss1-like transcript was also identified, but it appears to be non-functional due to the presence of a "p... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5538883 Wed, 07 Dec 2011 05:00:00 +0100 5538883 http://www.medworm.com/index.php?rid=5538886&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22154814%26dopt%3DAbstract Authors: Gonzalez R, Mohan H, Unniappan S Abstract The nucleobindins, nucleobindin 1 (NUCB1) and nucleobindin 2 (NUCB2), are homologous multidomain calcium and DNA binding proteins. NUCB1 is a well-characterized Golgi protein found within the rat pituitary, liver and kidney with functions related to immunity, calcium homeostasis and G protein signaling. NUCB2 is found both in the hypothalamus and brain stem centers, as well as peripherally in the digestive tract. Renewed interest in the nucleobindins has been sparked by the recent discovery of nesfatin-1, an endocrine factor post-translationally processed from the N-terminal of NUCB2. Nesfatin-1 has quickly established itself as a novel regulator of appetite, insulin secretion, energy homeostasis and reproduction with important con... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5538886 Sat, 03 Dec 2011 05:00:00 +0100 5538886 http://www.medworm.com/index.php?rid=5538885&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22155035%26dopt%3DAbstract Authors: Athauda S, Anderson T, de Nys R Abstract Asian Seabass, Lates calcarifer (Bloch, 1790), is a protandrous species cultured for Aquaculture. The cultured Asian Seabass in Australia exhibits precocious sex inversion before 2years of age. This phenomenon highly affects on maintaining a proper broodstock in a hatchery. The effect of temperature on sex inversion inducement in Asian Seabass was thus investigated at five different temperature regimes experienced in Australia. Asian Seabass (14months) grown in fresh water under natural temperature in a commercial farm in Queensland were transported to the research facility at James Cook University, Australia and held in fresh water at 28°C until acclimatized to the experimental conditions. Fish were acclimated to the experimental ... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5538885 Sat, 03 Dec 2011 05:00:00 +0100 5538885 http://www.medworm.com/index.php?rid=5538889&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22154571%26dopt%3DAbstract Authors: Celi M, Vazzana M, Sanfratello MA, Parrinello N Abstract In fish, interactions between Hsps and cortisol are involved in stress modulated physiological processes including innate immune responses. Cortisol exerts a role in the regulation of Hsps synthesis. Fish head kidney is a lymphomieloid and endocrine organ releasing cortisol, and it is the central organ for immune-endocrine interactions. In sea bass, cortisol intraperitoneal injection and in vitro treatment of head kidney cells show that inducible Hsp70 and Hsp90 are modulated by this hormone. However, an inverse relationship between mRNA expression (real-time PCR) and Hsp70 and Hsp90 protein levels (densitometric band analysis) was found. Time-course assays indicate a cortisol-mediated regulation. Furthermore, Hsp70 ... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5538889 Thu, 01 Dec 2011 05:00:00 +0100 5538889 http://www.medworm.com/index.php?rid=5538888&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22154572%26dopt%3DAbstract Authors: Moore BC, Forouhar S, Kohno S, Botteri NL, Hamlin HJ, Guillette LJ Abstract Oviducts respond to hormonal cues from ovaries with tissue proliferation and differentiation in preparation of transporting and fostering gametes. These responses produce oviducal microenvironments conducive to reproductive success. Here, we investigated changes in circulating plasma sex steroid hormones concentrations and ovarian and oviducal mRNA expression to an in vivo gonadotropin (FSH) challenge in sexually immature, five-month-old alligators. Further, we investigated differences in these observed responses between alligators hatched from eggs collected at a heavily-polluted (Lake Apopka, FL) and minimally-polluted (Lake Woodruff, FL) site. In oviducts, we measured mRNA expression of estrogen... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5538888 Thu, 01 Dec 2011 05:00:00 +0100 5538888 http://www.medworm.com/index.php?rid=5538887&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22154573%26dopt%3DAbstract Authors: Williams TD Abstract Life-histories provide a powerful, conceptual framework for integration of endocrinology, evolutionary biology and ecology. This has been a commonly articulated statement but here I show, in the context of avian reproduction, that true integration of ultimate and proximate approaches has been slow. We have only a rudimentary understanding of the physiological and hormonal basis of phenotypic variation in (a) reproductive traits that contribute most to individual variation in lifetime fitness in birds (e.g. laying date, clutch size, parental effort) and (b) trade-offs that link these traits or that link reproduction to other life stages (e.g. migration, molt). I suggest that some reasons for this relative lack of progress include (a) an increasingly red... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5538887 Thu, 01 Dec 2011 05:00:00 +0100 5538887 http://www.medworm.com/index.php?rid=5446942&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22099426%26dopt%3DAbstract Authors: Dores RM PMID: 22099426 [PubMed - in process] (Source: General and Comparative Endocrinology) General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5446942 Sat, 26 Nov 2011 06:48:39 +0100 5446942 http://www.medworm.com/index.php?rid=5446830&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22107840%26dopt%3DAbstract This study aimed at investigating the role of sexual steroids in the regulation of the expression of the single aromatase gene and steroid receptor subtypes in the brain-pituitary-gonadal axis of the Japanese eel. Unlike other teleosts, which possess duplicated genes for aromatase, cyp19a1a and cyp19a1b, expressed in the gonads and in the brain, respectively, eel species possess a single cyp19a1. Phylogenetic analysis indicated that eel brain/gonadal cyp19a1 branches at the basis of both teleost gonadal cyp19a1a and brain cyp19a1b clades. Female eels treated with catfish pituitary homogenate (CPH) to induce sexual maturation showed an increase in the expression of cyp19a1 and aromatase enzymatic activity in the brain and in the ovaries. Treatments with sex steroids (estradiol-17β, E(2) or... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5446830 Tue, 15 Nov 2011 05:00:00 +0100 5446830 http://www.medworm.com/index.php?rid=5446857&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22101208%26dopt%3DAbstract Authors: Romero LM Abstract Even though the term "stress" is widely used, a precise definition is notoriously difficult. Notwithstanding this difficulty, stress continues to be an important concept in biology because it attempts to describe how animals cope with environmental change under emergency conditions. Without a precise definition, however, it becomes nearly impossible to make testable a priori predictions about how physiological and hormonal systems will respond to emergency conditions and what the ultimate impact on the animal will be. The reactive scope model is a recent attempt to formulate testable predictions. This model provides a physiological basis to explain why corticosterone negative feedback, but not baseline corticosterone concentrations, corticosterone respon... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5446857 Sat, 12 Nov 2011 05:00:00 +0100 5446857 http://www.medworm.com/index.php?rid=5446932&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22100124%26dopt%3DAbstract Authors: Habibi HR, Nelson ER, Allan ER Abstract A number of studies have provided evidence for a link between thyroid hormones and physiological or pathophysiological conditions associated with reproduction. Most of the information available is based on clinical observations in human or research in mammals. There are also a number of studies in non-mammalian species, primarily investigating thyroid and reproductive endocrinology in isolation. The findings demonstrate that hyperthyroidism or hypothyroidism are associated with altered fertility due to changes in the levels and activities of hormones of the brain-pituitary-gonadal axis. There appears to be a consistent pattern based on a number of studies in mammalian and non-mammalian species, linking thyroid with reproduction. Resu... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5446932 Fri, 11 Nov 2011 05:00:00 +0100 5446932 http://www.medworm.com/index.php?rid=5428176&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22094207%26dopt%3DAbstract This study evaluated LH release effectiveness of the most commonly used GnRHa and clarified whether LH secretion followed by ovulation is subject to inhibitory dopaminergic control in tench. Fish were intraperitoneally injected with three types of GnRHa, GnRHa with dopamine inhibitor metoclopramide (combined treatment), or the dopamine inhibitor metoclopramide alone. LH concentrations at five sampling times (0, 6, 12, 24, and 33h) together with ovulation success and fecundity index were recorded. The combined treatment triggered an almost immediate LH release peak with a gradual decline, and resulted in a high ovulation rate. In contrast to the combined treatment, an application of GnRHa alone at 10μgkg(-1) induced gradual increase of LH concentrations with peaks close to ovulation time, ... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5428176 Thu, 10 Nov 2011 05:00:00 +0100 5428176 http://www.medworm.com/index.php?rid=5428175&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22094208%26dopt%3DAbstract Authors: Kling P, Jönsson E, Nilsen TO, Einarsdottir IE, Rønnestad I, Stefansson SO, Björnsson BT Abstract The growth-promoting effects of in vivo growth hormone (GH) treatment were studied in relation to size and lipid content of energy stores including liver, mesentery, white muscle and belly flap in rainbow trout. In order to elucidate endocrine interactions and links to regulation of growth, adiposity and energy metabolism, plasma levels of GH, insulin-like growth factor I (IGF-I), leptin (Lep) and ghrelin, were assessed and correlated to growth and energy status. In addition tissue-specific expression of lepa1 mRNA was examined. Juvenile rainbow trout were implanted with sustained-release bovine GH implants and terminally sub-sampled at 1, 3 and 6weeks. GH increased specifi... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5428175 Thu, 10 Nov 2011 05:00:00 +0100 5428175 http://www.medworm.com/index.php?rid=5428189&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22080042%26dopt%3DAbstract Authors: Yang DB, Xu YC, Wang DH Abstract Temperate rodent species experience marked seasonal fluctuations in environmental temperatures. High thermoregulatory demands during winter usually weaken immune function. Brown adipose tissue (BAT) plays a crucial role in adaptive thermoregulatory process. Thus, we proposed the hypothesis that BAT might participate in the regulation of seasonal changes in immune function. The present study examined the trade-off between thermoregulation and immune function and the potential role of BAT in regulating seasonal changes in immune function in Mongolian gerbils. Specifically, surgical removal of interscapular BAT (34% of total BAT) was performed in male gerbils, and subsequently acclimated to either warm (23±1°C) or cold (4±1°C) conditions. ... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5428189 Thu, 03 Nov 2011 04:00:00 +0100 5428189 http://www.medworm.com/index.php?rid=5428195&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22057000%26dopt%3DAbstract Authors: Ocampo Daza D, Lewicka M, Larhammar D Abstract The vertebrate oxytocin and vasopressin receptors form a family of G-protein-coupled receptors (GPCRs) that mediate a large variety of functions, including social behavior and the regulation of blood pressure, water balance and reproduction. In mammals four family members have been identified, three of which respond to vasopressin (VP) named V1A, V1B and V2, and one of which is activated by oxytocin (OT), called the OT receptor. Four receptors have been identified in chicken as well, but these have received different names. Until recently only V1-type receptors have been described in several species of teleost fishes. We have identified family members in several gnathostome genomes and performed phylogenetic analyses to classi... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5428195 Fri, 28 Oct 2011 04:00:00 +0100 5428195 http://www.medworm.com/index.php?rid=5383411&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22051321%26dopt%3DAbstract Authors: Cho HK, Kong HJ, Kim HY, Cheong J Abstract Peroxisome proliferator-activated receptors (PPARs) are nuclear hormone receptors that play key roles in lipid and energy homeostasis. Paralichthys olivaceus PPARα (PoPPARα) cDNA was isolated by initial reverse transcription-polymerase chain reaction (RT-PCR) using conserved region among fish species and rapid amplification of cDNA ends (RACE). The full-length of PoPPARα cDNA is 2040-bp long encoding a polypeptide with 505 amino acids and containing a DNA binding domain (C4-type zinc finger) and a ligand-binding domain. PoPPARα was detected from 1day post-hatch and was highly expressed in the stomach, liver, and intestine of continuously fed flounder, approximately 16cm in size. PoPPARα mRNA expression was down-regulated in t... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5383411 Tue, 25 Oct 2011 04:00:00 +0100 5383411 http://www.medworm.com/index.php?rid=5383413&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22036890%26dopt%3DAbstract Authors: Hevrøy EM, Waagbø R, Torstensen BE, Takle H, Stubhaug I, Jørgensen SM, Torgersen T, Tvenning L, Susort S, Breck O, Hansen T Abstract Due to global and local climate changes, farmed salmon may experience periods of elevated sea temperatures. An experiment was conducted to examine endocrine and dietary effects of high sea temperatures in adult (2.0kg) and sexually immature Atlantic salmon, Salmo salar L. Groups of salmon were exposed to 19°C while others were kept as controls at 14°C. The experiment lasted for 56days, and fish were given iso-nitrogenous diets with either a normal (335gkg(-1); L34) or a lower lipid level (298gkg(-1); L30). Fish held at 19°C had a reduction in the daily feed intake, growth and feed utilization of less than 50% compared to the controls. F... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5383413 Fri, 21 Oct 2011 04:00:00 +0100 5383413 http://www.medworm.com/index.php?rid=5383412&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22036891%26dopt%3DAbstract Authors: Michael Conlon J, Mechkarska M, King JD Abstract African clawed frogs of the Xenopodinae (Xenopus+Silurana) constitute a well-defined system in which to study the evolutionary trajectory of duplicated genes and are a source of antimicrobial peptides with therapeutic potential. Allopolyploidization events within the Xenopodinae have given rise to tetraploid, octoploid, and dodecaploid species. The primary structures and distributions of host-defense peptides from the tetraploid frogs Xenopus borealis, Xenopusclivii, Xenopuslaevis, Xenopusmuelleri, "X. muelleri West", and Xenopus petersii may be compared with those from the octoploid frogs Xenopus amieti and X. andrei. Similarly, components in skin secretions from the diploid frog Silurana tropicalis may be compared with tho... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5383412 Fri, 21 Oct 2011 04:00:00 +0100 5383412 http://www.medworm.com/index.php?rid=5383416&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22036840%26dopt%3DAbstract Authors: Burrone L, Raucci F, Di Fiore MM Abstract Previous studies have provided evidence that d-Asp plays a role in steroid-mediated reproductive biology in amphibians, reptiles, birds and mammals. To examine the molecular involvement of d-Asp on steroidogenic pathway regulation, we analysed the expression of StAR, P450 aromatase and 5αRed2 mRNAs in Pelophylax esculentus testis, either in relation to the reproductive cycle or d-Asp treatment. Basal StAR mRNA levels, as well as d-Asp and testosterone concentrations, were higher in reproductive than in post-reproductive frogs. d-Asp treatment increased StAR mRNA expression and immunolocalisation in both the reproductive and post-reproductive periods. In control testis, aromatase mRNA levels were higher in the post-reproductive per... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5383416 Thu, 20 Oct 2011 04:00:00 +0100 5383416 http://www.medworm.com/index.php?rid=5383415&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22036841%26dopt%3DAbstract Authors: Trudeau VL, Martyniuk CJ, Zhao E, Hu H, Volkoff H, Decatur WA, Basak A Abstract Numerous small potentially bioactive peptides are derived from the selective processing of the ∼600 amino acid secretogranin II (SgII) precursor, but only the 31-42 amino acid segment termed secretoneurin (SN) is well-conserved from sharks to mammals. Both SNa and SNb paralogs have been identified in some teleosts, likely arising as a result of the specific genome duplication event in this lineage. Only one copy of the putative lamprey SgII (188 amino acids) could be identified which gives rise to a divergent agnathan SN that contains the signature YTPQ-X-LA-X(7)-EL sequence typical of the central core of all known SN peptides. In rodent models, SN has regulatory effects on neuroinflammation ... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5383415 Thu, 20 Oct 2011 04:00:00 +0100 5383415 http://www.medworm.com/index.php?rid=5383414&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22036842%26dopt%3DAbstract Authors: Seale AP, Watanabe S, Grau EG Abstract Osmoregulation is essential to life in vertebrates and osmoreception is a fundamental element in osmoregulation. Progress in characterizing the mechanisms that mediate osmoreception has been made possible by using a uniquely accessible cell model, the prolactin (PRL) cell of the euryhaline tilapia, Oreochromis mossambicus. In addition to a brief historical overview, we offer a summary of our recent progress on signal transduction and osmosensitivity in the tilapia PRL cell model. Prolactin is a central regulator of hydromineral balance in teleosts in freshwater (FW). Consistent with its essential role in FW osmoregulation, PRL release in tilapia is inversely related to extracellular osmolality, both in vivo and in vitro. Osmotically-d... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5383414 Thu, 20 Oct 2011 04:00:00 +0100 5383414 http://www.medworm.com/index.php?rid=5383418&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22033221%26dopt%3DAbstract In this study, we applied tritiated estradiol to the eggs of red-eared sliders (Trachemys scripta) at the time of oviposition and characterized the subsequent metabolism and movement throughout embryonic development. Results indicate that very early in development, estradiol is converted to a variety of water-soluble estrogen sulfates that reside in the yolk and extraembryonic fluids until late in development. Within the final stages of development, we observe a significant decline in the total amount of metabolites present in the yolk and extraembryonic fluids and a significant increase in the amount of metabolites present in the embryo. While estradiol metabolism occurs during the early stages of development, the later stages appear to be the most dynamic with regards to the movement of ... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5383418 Tue, 18 Oct 2011 04:00:00 +0100 5383418 http://www.medworm.com/index.php?rid=5383419&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22026959%26dopt%3DAbstract Authors: Lim W, Ahn SE, Jeong W, Kim JH, Kim J, Lim CH, Bazer FW, Han JY, Song G Abstract Serine protease inhibitors (SERPINs) comprise the largest superfamily of protease inhibitors and appear to be ubiquitously expressed in a variety of species. Of these, squamous cell carcinoma antigen 1 (SCCA1), also known as a SERPINB3, was first identified in squamous cell carcinoma tissue from the cervix of women. However, there is little known about the expression and hormonal regulation of SERPINB3 in chickens. Therefore, the avian SERPINB3 gene was compared with those of other species with respect to structure, phylogenetic evolution and tissue- and cell-specific expression in hens. Chicken SERPINB3 has moderate homology to mammalian SERPINB3 proteins (36-47%). Of particular note, SERPINB... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5383419 Mon, 17 Oct 2011 04:00:00 +0100 5383419 http://www.medworm.com/index.php?rid=5383420&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22020257%26dopt%3DAbstract We describe seasonal patterns of hormonal secretion, moult, and parental behaviour in sibling species of giant petrels (Macronectes spp.) which begin moult during the incubation/early chick-rearing stage of reproduction. With the exception of male Southern giant petrels (Macronectes giganteus), prolactin secretion and moult in Northern (Macronectes halli) and female Southern giant petrels conformed to those observed in all other avian species, with the initiation of moult coincident with decreases from peak prolactin levels. However, male Southern giant petrels began moulting early in incubation when prolactin was increasing and had not yet peaked, which suggests a requirement of prolactin for incubation behaviour and a dissociation of prolactin from moult. Corticosterone showed little sea... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5383420 Sat, 15 Oct 2011 04:00:00 +0100 5383420 http://www.medworm.com/index.php?rid=5383417&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22033222%26dopt%3DAbstract This study is the first to assess the reproductive phases of female Asian elephants based on the correlative-patterns of both the fecal 5α-P-3OH and serum P(4) values over multiple estrous cycles. This has a potential application in the reproductive management and conservation of Asian elephants. PMID: 22033222 [PubMed - as supplied by publisher] (Source: General and Comparative Endocrinology) General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5383417 Fri, 14 Oct 2011 04:00:00 +0100 5383417 http://www.medworm.com/index.php?rid=5383423&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22019478%26dopt%3DAbstract In this study, we investigated the effect of feed-restriction on leptin genes (lepa1 and lepa2), leptin receptor (lepr) gene expression and plasma leptin levels in juvenile Atlantic salmon parr. Feed restriction was performed from late April to mid-June, in order to gain insight into the role of the leptin system in energy balance regulation and adiposity in juvenile salmon. A significant increase in lepa1 expression as well as higher levels of plasma leptin was found in feed-restricted fish in June compared to fully fed controls, while lepa2 gene expression decreased in both groups during the treatment period. Lepa2 was, however significantly higher in the feed-restricted group in June. Leptin receptor expression was up regulated during the period of enhanced growth and lipid deposition i... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5383423 Wed, 12 Oct 2011 04:00:00 +0100 5383423 http://www.medworm.com/index.php?rid=5383422&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22019479%26dopt%3DAbstract Authors: Aroua S, Maugars G, Jeng SR, Chang CF, Weltzien FA, Rousseau K, Dufour S Abstract European eels are blocked at a prepubertal silver stage due to a deficient production of pituitary gonadotropins. We investigated the potential role of activin/follistatin system in the control of eel gonadotropins. Through the development of qPCR assays for European eel activin β(B) and follistatin, we first analyzed the tissue distribution of the expression of these two genes. Both activin β(B) and follistatin are expressed in the brain, pituitary and gonads. In addition, a striking expression of both transcripts was also found in the retina and in adipose tissue. The effects of recombinant human activins and follistatin on eel gonadotropin gene expression were studied using primary cultu... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5383422 Wed, 12 Oct 2011 04:00:00 +0100 5383422 http://www.medworm.com/index.php?rid=5383424&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22015989%26dopt%3DAbstract In conclusion, the GnRHa implants activated effectively the reproductive endocrine axis in captive Atlantic bluefin tuna broodstocks, through stimulation of sustained elevations in plasma LH, which in turn evoked the synthesis and secretion of the relevant sex steroids leading to gamete maturation and release. PMID: 22015989 [PubMed - as supplied by publisher] (Source: General and Comparative Endocrinology) General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5383424 Mon, 10 Oct 2011 04:00:00 +0100 5383424 http://www.medworm.com/index.php?rid=5383421&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22019531%26dopt%3DAbstract Authors: Günther J, Díaz V, Pedernera E, Méndez C Abstract Cadherins are adhesion molecules that play a crucial role in tissue morphogenesis. Studies on N-cadherin and E-cadherin in the ovary of fetal hamster suggest that these adhesion molecules are involved in primordial follicle formation. In chicken embryo, present results demonstrate that N-cadherin is located on the surface epithelium and in the cortical cords of the ovary. Moreover, N-cadherin is identified in germ cells on day 14 of chicken embryo development. Quantification of mRNA of N-cadherin and E-cadherin demonstrates that treatments with follicle-stimulating hormone (FSH) or human chorionic gonadotropin (hCG), increase N-cadherin expression. Whereas, E-cadherin expression is decreased by gonadotropin treatments. T... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5383421 Mon, 10 Oct 2011 04:00:00 +0100 5383421 http://www.medworm.com/index.php?rid=5332769&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22001502%26dopt%3DAbstract Authors: Peter VS, Peter MC Abstract Endocrines, the chief components of chemical centers which produce hormones in tune with intrinsic and extrinsic clues, create a chemical bridge between the organism and the environment. In fishes also hormones integrate and modulate many physiologic functions and its synthesis, release, biological actions and metabolic clearance are well regulated. Consequently, thyroid hormones (THs) and cortisol, the products of thyroid and interrenal axes, have been identified for their common integrative actions on metabolic and osmotic functions in fish. On the other hand, many anthropogenic chemical substances, popularly known as endocrine disrupting chemicals, have been shown to disrupt the hormone-receptor signaling pathways in a number fish species. Th... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5332769 Wed, 05 Oct 2011 04:00:00 +0100 5332769 http://www.medworm.com/index.php?rid=5317267&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21986088%26dopt%3DAbstract Authors: Graham SP, Earley RL, Guyer C, Mendonça MT Abstract Squamates (lizards and snakes) have independently evolved viviparity over 100 times, and exhibit a wide range of maternal investment in developing embryos from the extremes of lecithotrophic oviparity to matrotrophic viviparity. This group therefore provides excellent comparative opportunities for studying endocrine and immune involvement during pregnancy, and their possible interactions. We studied the cottonmouth (Agkistrodon piscivorus), since they exhibit limited placentation (e.g., ovoviviparity), allowing comparison with squamate species hypothesized to require considerable maternal immune modulation due to the presence of a more extensive placental connection. Furthermore, the cottonmouth's biennial reproductive c... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5317267 Sun, 02 Oct 2011 04:00:00 +0100 5317267 http://www.medworm.com/index.php?rid=5317265&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21986090%26dopt%3DAbstract Authors: Shahbazi M, Schmidt M, Carruth LL Abstract Stress has long lasting effects on physiology, development, behavior, reproductive success and the survival of an individual. These effects are mediated by glucocorticoids, such as corticosterone, via glucocorticoid receptors (GR), however the exact mechanisms underlying these effects are unknown. GR have been widely studied in mammals but little is known about GR in other vertebrate groups, especially songbirds. We investigated the distribution, quantity, and subcellular-localization of GR-immunoreactive (GRir) neurons in the brains of male zebra finches on P10 (post-hatch day 10, song nuclei formed), and in adulthood (post-hatch day 90 or older) using immunohistochemistry. GRir neurons were widely distributed in the brains of ma... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5317265 Sun, 02 Oct 2011 04:00:00 +0100 5317265 http://www.medworm.com/index.php?rid=5317270&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21983173%26dopt%3DAbstract Authors: Preis A, Mugisha L, Hauser B, Weltring A, Deschner T Abstract The primary male androgen testosterone (T) is often used as an endocrinological marker to investigate androgen-behaviour interactions in males. In chimpanzees and bonobos, studies investigating the relationship between T levels and dominance rank or aggressive behaviour have revealed contradictory results. The immunoassays used in these studies were originally developed for the measurement of steroids in serum. Their application to non-invasively collected samples, however, can lead to methodological problems due to cross-reacting metabolites, which might occur in urine or faeces but not in blood. The overall aim of this study, therefore, is to clarify whether a T enzyme immunoassay (EIA) is an applicable method... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5317270 Sat, 01 Oct 2011 04:00:00 +0100 5317270 http://www.medworm.com/index.php?rid=5317268&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21986087%26dopt%3DAbstract We examined the ability of male and female Northern Cardinals (Cardinalis cardinalis) to elevate gonadal T following standardized injections of gonadotropin-releasing hormone (GnRH) across three non-breeding seasons. Males and females were capable of significantly elevating gonadal T production following GnRH injections during periods of reproductive quiescence. The magnitude of T elevation varied across the non-breeding season, but not between sexes. To our knowledge, this is the first report of a significant increase in gonadal T production following GnRH injections administered in the non-breeding season. PMID: 21986087 [PubMed - as supplied by publisher] (Source: General and Comparative Endocrinology) General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5317268 Sat, 01 Oct 2011 04:00:00 +0100 5317268 http://www.medworm.com/index.php?rid=5317266&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21986089%26dopt%3DAbstract Authors: Boggs AS, Hamlin HJ, Lowers RH, Guillette LJ Abstract Thyroid hormones, essential for normal growth and health, are associated with changes in temperature, photoperiod, and reproduction. Iodide, a necessary element for thyroid hormone production, varies in diet, and is more abundant in estuarine environments, which could alter thyroid hormone variation. However, associations between thyroid hormone concentrations in animals from marine versus freshwater environments, which could become more pertinent with rising sea levels associated with global climate change, are not well studied. To determine the importance of dietary iodide in seasonal variation of plasma thyroid hormone concentrations, we analyzed seasonal variation of thyroxine (T(4)) and triiodothyronine (T(3)) conc... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5317266 Sat, 01 Oct 2011 04:00:00 +0100 5317266 http://www.medworm.com/index.php?rid=5317271&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21978589%26dopt%3DAbstract Authors: García-López A, Sánchez-Amaya MI, Halm S, Astola A, Prat F Abstract Vertebrate oocytes actively contribute to follicle development by secreting a variety of growth factors, among which bone morphogenetic protein 15 (BMP15/Bmp15) and growth differentiation factor 9 (GDF9/Gdf9) have been paid particular attention. In the present study, we describe the cellular localization, the developmental profiles, and the response to unilateral ovariectomy (a procedure implying the surgical removal of one of the ovaries) of protein and mRNA steady-state levels of Bmp15 and Gdf9 in the ovary of European sea bass, an important fish species for marine aquaculture industry. In situ hybridization and immunohistochemistry demonstrated that the oocyte is the main production site of Bmp15 and... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5317271 Thu, 29 Sep 2011 04:00:00 +0100 5317271 http://www.medworm.com/index.php?rid=5317269&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21983423%26dopt%3DAbstract Authors: Giuseppina DG, Marina P, Marisa A, Mariailaria V, Ermelinda L, Piero A Abstract In vertebrates, the liver was long thought to be the only site of vitellogenin (Vtg) production, but recent studies demonstrated that Vtg is also expressed in extrahepatic districts. The aim of this paper is to assess, by in situ hybridization and immunohistochemistry, the expression of Vtg in the testis and kidney of Torpedo marmorata exposed to 17β-estradiol (E(2)). In treated samples vtg mRNA and Vtg were detected contemporaneously only in the testis; differently the kidney cells were positive to Vtg antibody, but negative to vtg mRNA. This is the first study to assess that male germ cells, after an exposure to E(2), synthesize Vtg in a stage-dependent manner. The presence of Vtg and the mo... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5317269 Thu, 29 Sep 2011 04:00:00 +0100 5317269 http://www.medworm.com/index.php?rid=5284250&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21963864%26dopt%3DAbstract In conclusion, we demonstrate here that adrenal glands of Libyan jird and gerbil express both an ortholog of the murine/rat Akr1b7gene and that ACTH-responsiveness is at least conserved in Libyan jird. PMID: 21963864 [PubMed - as supplied by publisher] (Source: General and Comparative Endocrinology) General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5284250 Thu, 22 Sep 2011 04:00:00 +0100 5284250 http://www.medworm.com/index.php?rid=5284249&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21963960%26dopt%3DAbstract Authors: Carvalho ES, Fuentes J, Power DM Abstract The skin is the largest organ in the body and is a barrier between the internal and external environment. The present study evaluates how PTU, a goitrogen, that is used to treat hyperthyroidism affects the structure and electrical properties of the frog (Xenopus laevis) skin. The results are considered in the context of the two-membrane model established in the seminal work of Ussing and collegues in the 1940s and 1950s. In vitro experiments with skin from Xenopus adults revealed that PTU can act directly on skin and causes a significant increase (p<0.05, One-way ANOVA) in short circuit current (Isc) via an amiloride-insensitive mechanism. Juvenile Xenopus exposed to waterborne PTU (5mg/L) had a significantly bigger and more act... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5284249 Thu, 22 Sep 2011 04:00:00 +0100 5284249 http://www.medworm.com/index.php?rid=5284248&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21963961%26dopt%3DAbstract Authors: Hinfray N, Baudiffier D, Leal MC, Porcher JM, Aït-Aïssa S, Le Gac F, Schulz RW, Brion F Abstract The aim of the present study was to characterize P450 17α-hydroxylase/17,20-lyase (cyp17a1) expression in zebrafish and to assess the effect of the pharmaceutical clotrimazole, a known inhibitor of various cytochrome P450 enzyme activities, on testicular gene and protein expression of this enzyme as well as on the testicular release of 11-ketotestosterone (11-KT), a potent androgen in fish. We first showed that cyp17a1 is predominantly expressed in gonads of zebrafish, notably in male. In vivo, clotrimazole induced a concentration-dependent increase of cyp17a1 gene expression and Cyp17-I protein synthesis in zebrafish testis. Using zebrafish testicular explants, we further s... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5284248 Thu, 22 Sep 2011 04:00:00 +0100 5284248 http://www.medworm.com/index.php?rid=5284254&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21945117%26dopt%3DAbstract Authors: Sreenivasulu G, Senthilkumaran B, Sridevi P, Rajakumar A, Rasheeda MK Abstract The maturation inducing hormone, 17α,20β-dihydroxy-4-pregnen-3-one (17α,20β-DP) required for the meiotic maturation is produced from the precursor 17α-hydroxyprogesterone by the enzyme 20β-hydroxysteroid dehydrogenase (20β-HSD) in several teleosts. Central role of 20β-HSD in ovarian cycle and final oocyte maturation is well studied when compared to spermatogenesis. In the present study, we investigated the localization and expression of 20β-HSD in testicular cycle and gonadotropin induced sperm maturation. During testicular ontogeny, 20β-HSD expression was detectable at 50 and 100days post-hatch (dph), while the expression was high at 150dph. In testicular cycle, highest levels of mRNA... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5284254 Fri, 16 Sep 2011 04:00:00 +0100 5284254 http://www.medworm.com/index.php?rid=5284253&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21945119%26dopt%3DAbstract Authors: Yayou KI, Kitagawa S, Ito S, Kasuya E, Sutoh M Abstract As a preliminary step to elucidate the involvement of central neurotransmitters in the dip in voluntary feed intake during the perinatal period in cows, we investigated the effect of intracerebroventricular (ICV) administration of oxytocin, prolactin-releasing peptide (PrRP), or corticotropin-releasing hormone (CRH), the central functions of all of which undergo drastic changes during the perinatal period, on feed intake in steers. Thirty minutes before the onset of feeding, the treatment solution was injected into the third ventricle through an implanted cannula, and feeding-related behaviors were observed for 1h after the onset of feeding. Neither ICV oxytocin (5 and 50μg) nor PrRP (2 and 20nmol) reduced feed intak... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5284253 Fri, 16 Sep 2011 04:00:00 +0100 5284253 http://www.medworm.com/index.php?rid=5284251&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21945118%26dopt%3DAbstract Authors: Narayan EJ, Molinia FC, Kindermann C, Cockrem JF, Hero JM Abstract Toe-clipping, the removal of one or more toes, is a common method used to individually mark free-living animals. Whilst this method is widely used in studies of amphibians, the appropriateness of the method, and its potential detrimental effects have been the subject of debate. Here, we provide for the first time, evidence that toe-clipping is a stressor in a wild amphibian. We measured urinary corticosterone responses of male cane toads (Rhinella marina) to capture and handling only, and to toe-clipping under field conditions. Urinary testosterone concentrations and white blood cell proportions were also measured. Urinary corticosterone metabolite concentrations increased 6h after capture and handling only... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5284251 Fri, 16 Sep 2011 04:00:00 +0100 5284251 http://www.medworm.com/index.php?rid=5284247&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21945120%26dopt%3DAbstract Authors: Li L, Fu YC, Xu JJ, Chen XC, Lin XH, Luo LL Abstract The insulin-like growth factor-1 (IGF-1) plays an important role in the regulation of reproductive function. In the present study, we examined the effects of caloric restriction (CR) on the reproductive lifespan in rats and investigated the potential role of IGF-1. After 10weeks of treatment, we determined the distribution of the ovarian follicles at various stages and measured the plasma level of IGF-1, luteinizing hormone (LH), follicle-stimulating hormone (FSH), and estrogen (ESG). Our results show that IGF-1 level was decreased after CR and correlated with the decrease in the levels of LH, FSH and ESG. Moreover, a higher percentage of primordial follicles and surviving follicles was observed in CR rats than in contro... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5284247 Fri, 16 Sep 2011 04:00:00 +0100 5284247 http://www.medworm.com/index.php?rid=5284252&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21933675%26dopt%3DAbstract Authors: Gayrard V, Picard-Hagen N, Viguié C, Toutain PL Abstract A model of thyroidectomized sheep intravenously supplemented with thyroid hormone (TH) was developed to mimic endogenous TH exposure and to analyze the impact on plasma TH homeostasis of xenobiotic interference with TH binding to plasma proteins. TH was displaced from plasma protein binding sites by using phenylbutazone (PBZ) as a test xenobiotic, to compare the effect of PBZ on steady state free and total plasma TH concentrations between the in vivo situation and an in vitro system. While PBZ increased free TH in vitro, PBZ administration in vivo produced an immediate reduction in both total and free plasma TH. The decrease in the total TH was consistent with a PBZ-induced displacement of TH from its plasma binding... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5284252 Sat, 10 Sep 2011 04:00:00 +0100 5284252 http://www.medworm.com/index.php?rid=5284255&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21930130%26dopt%3DAbstract Authors: Fair PA, Montie E, Balthis L, Reif JS, Bossart GD Abstract Thyroid hormones (TH) are key regulators of metabolism and development, yet our understanding of the variability in serum TH concentrations in free-ranging marine mammals is limited. Thus, we examined the interrelationships between TH and age, sex, reproductive status, geographic location, and ocean temperatures in wild bottlenose dolphins (Tursiops truncatus). Circulating concentrations of TH (total thyroxine (tT(4)), free T(4) (fT(4)), and total triiodothyronine (tT(3))) were determined in a total of 195 dolphins; 80 from the coastal waters of Charleston, South Carolina (CHS) and 115 from the Indian River Lagoon, Florida (IRL). Age had the most influence on circulating TH concentrations in dolphins at both sites ... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5284255 Fri, 09 Sep 2011 04:00:00 +0100 5284255 http://www.medworm.com/index.php?rid=5235177&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21925177%26dopt%3DAbstract Authors: Tropea C, Hermida GN, López Greco LS Abstract This work investigates the effects of androgenic gland (AG) ablation on the structure of the reproductive system, development of secondary sexual characters and somatic growth in Cherax quadricarinatus males. The AG ablation, which was performed at an early developmental stage (initial weight: 1.85±0.03g), had no effect on the somatic growth parameters (specific growth rate and growth increment), but it prevented the re-formation of male gonopores and appendices masculinae. However, the red patch differentiation and chelae size were similar to those in control males. All the ablated animals developed a male reproductive system. Testis structure was macroscopically and histologically normal. The distal portion of the vas defer... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5235177 Wed, 07 Sep 2011 04:00:00 +0100 5235177 http://www.medworm.com/index.php?rid=5235176&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21925178%26dopt%3DAbstract Authors: Zajac DM, Cerasale DJ, Landman S, Guglielmo CG Abstract The migratory flights of birds are fuelled largely by fatty acids. Fatty acid transporters, including FAT/CD36, FABPpm and H-FABP, and enzymes involved in fatty acid oxidation (CPT, CS, HOAD) are seasonally up-regulated in flight muscle to meet the demands of this intense aerobic exercise. The mechanisms that control these biochemical changes in response to migration are mostly unknown. We studied the effects of a photoperiod-induced migratory state and a 7day treatments with murine leptin (1μg/g body mass, twice per day) on fatty acid metabolism in captive white-throated sparrows. Sparrows that were exposed to a long-day migratory photoperiod increased flight muscle FAT/CD36 and H-FABP mRNA by 154% and 589%, respect... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5235176 Wed, 07 Sep 2011 04:00:00 +0100 5235176 http://www.medworm.com/index.php?rid=5235175&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21925179%26dopt%3DAbstract Authors: Cerasale DJ, Zajac DM, Guglielmo CG Abstract The hormone leptin is involved in the regulation of energy balance in mammals, mainly by reducing food intake and body adiposity and increasing energy expenditure. During energetically demanding periods, leptin's action is often altered to facilitate fat deposition and maintain high rates of food intake. Despite the present controversy over the existence of an avian leptin, there is evidence that a leptin receptor exists in birds and its activation influences energy intake and metabolism. However, it is unknown whether the effects of the activation of leptin receptor on energy balance are modulated during migration. We manipulated photoperiod to induce migratory behavior in captive white-throated sparrows (Zonotrichia albicollis... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5235175 Wed, 07 Sep 2011 04:00:00 +0100 5235175 http://www.medworm.com/index.php?rid=5235174&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21925180%26dopt%3DAbstract Authors: Landys MM, Goymann W, Slagsvold T Abstract In captivity, the adrenocortical stress response can be permanently altered by events that occur during early life. Free-living animals have rarely been examined in this regard. To examine whether early-life events impact the hypothalamo-pituitary-adrenal (HPA) axis in the natural setting, we evaluated the stress response of free-living interspecifically cross-fostered great tits (Parus major). Cross-fostered birds may show a long-term potentiation of the adrenocortical stress response because species-specific nutritional requirements may not be met in the nest and/or cross-fostered birds may experience psychosocial stress while being raised by heterospecifics. Nevertheless, we hypothesized that in the natural setting, programmed ... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5235174 Wed, 07 Sep 2011 04:00:00 +0100 5235174 http://www.medworm.com/index.php?rid=5235173&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21925503%26dopt%3DAbstract Authors: Pinson SE, Wilson JL, Navara KJ Abstract Biases in avian sex ratios have been documented in relation to a variety of social and environmental conditions. Previous studies suggest that treatment with hormones can stimulate females to manipulate offspring sex, and that this effect occurs before ovulation. For example, acute and chronic treatments with testosterone stimulated significant skews towards male offspring. Hormones may act by influencing which sex chromosome is donated by the heterogametic female bird into the oocyte. However, it is difficult to pinpoint when effects of testosterone on offspring sex occurred in previous experiments because testosterone treatments were given either chronically over the entire period of follicular development or many hours before the... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5235173 Fri, 02 Sep 2011 04:00:00 +0100 5235173 http://www.medworm.com/index.php?rid=5221685&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21910992%26dopt%3DAbstract Authors: Subhash Peter MC, Rejitha V Abstract The interactive effects of ambient acidity and salinity on thyroid function are less understood in fish particularly in air-breathing fish. We, therefore, examined the thyroid function particularly the osmotic and metabolic competences of freshwater (FW) and salinity-adapted (SA; 20ppt) air-breathing fish (Anabas testudineus) during acidic and post-acidic acclimation, i.e., during the exposure of fish to either acidified water (pH 4.2 and 5.2) for 48h or clean water for 96h after pre-exposure. A substantial rise in plasma T(4) occurred after acidic exposure of both FW and SA fish. Similarly, increased plasma T(3) and T(4) were found in FW fish kept for post-acidic acclimation and these suggest an involvement of THs in short-term acidic ... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5221685 Fri, 02 Sep 2011 04:00:00 +0100 5221685 http://www.medworm.com/index.php?rid=5221686&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21907716%26dopt%3DAbstract Authors: Li S, Tomić M, Stojilkovic SS Abstract Our previous studies have showed that Pannexin 1 (Panx1), a member of a recently discovered family of gap junction proteins, is expressed in the pituitary gland. Here we investigated the presence and expression pattern of Panx1 isoforms in pituitary cells, their roles in ATP release, and their association with purinergic P2X receptor subtypes that are native to pituitary cells. In addition to the full-size Panx1, termed Panx1a, pituitary cells also express two novel shorter isoforms, termed Panx1c and Panx1d, which formation reflects the existence of alternative splicing sites in exons 2 and 4. Panx1c is lacking the Phe108-Gln180 sequence and P2X1d is missing the Val307-Cys426 C-terminal end sequence. Confocal microscopy and biotin l... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5221686 Thu, 01 Sep 2011 04:00:00 +0100 5221686 http://www.medworm.com/index.php?rid=5112648&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21745476%26dopt%3DAbstract Authors: Taniuchi S, Maeda K, Kudo T, Takahashi S, Takeuchi S Pit-1 is a pituitary-specific transcription factor responsible for pituitary development and hormone expression in mammals. Alternative splicing of Pit-1 gene transcripts has been shown to give rise to several variants with discrete transactivation properties; however, those arising from alternative promoters such as avian Pit-1w have not yet been identified in mammals. Here, comparative genomics analysis followed by reverse transcription-polymerase chain reaction (RT-PCR) and rapid amplification of 5' cDNA ends (5'RACE) were used in identifying Pit-1w mRNA in the mouse pituitary. The mouse Pit-1w mRNA is generated by using an alternative promoter located in the first intron, as with chicken Pit-1w, and is expressed in a wid... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5112648 Thu, 11 Aug 2011 07:48:37 +0100 5112648 http://www.medworm.com/index.php?rid=5112647&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21756910%26dopt%3DAbstract This study has shown individual corticosterone responses of amphibians for the first-time, and has provided a novel method for quantifying the relative amount of variation in amphibian corticosterone responses. PMID: 21756910 [PubMed - in process] (Source: General and Comparative Endocrinology) General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5112647 Thu, 11 Aug 2011 07:48:30 +0100 5112647 http://www.medworm.com/index.php?rid=5112639&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21821034%26dopt%3DAbstract In conclusion NWP pancreatic islets express comparable islet cell types and distribution to humans and pigs. Importantly, marmosets have a similar glucose transporter profile to humans, making this non-endangered primate species a useful animal model for pancreatic biology. PMID: 21821034 [PubMed - as supplied by publisher] (Source: General and Comparative Endocrinology) General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5112639 Thu, 28 Jul 2011 23:00:00 +0100 5112639 http://www.medworm.com/index.php?rid=5112641&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21819986%26dopt%3DAbstract In this study we investigated the role of the innate immunity of the oviductal mucosa of Xenopus laevis, an amphibian characterized by external fertilization. In particular we examined the expression and localization of Interleukin-1β (IL1B), Macrophage migration inhibitory factor (MIF) and Interleukin-1 receptor type 1 (IL1R1) in different oviductal portions including an upper glandular region, an intermediate and a lower aglandular region (the ovisac). Tissues were examined by immunohistochemistry and western blot using polyclonal antibodies against human molecules. IL1B, MIF and IL1R1 were all shown in the three oviductal regions examined, albeit with a general increase towards the external environment. A substantial difference among the cytokine components was also observed mainly in ... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5112641 Tue, 26 Jul 2011 23:00:00 +0100 5112641 http://www.medworm.com/index.php?rid=5112640&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21819987%26dopt%3DAbstract Authors: Kozlowski CP, Ricklefs RE Birds in multi-nestling broods often experience reduced growth and elevated nutritional and social stress as a result of competition for parental resources. While responses are often species-specific, experimentally increasing brood size has been shown to decrease growth and increase production of both testosterone and corticosterone in nestling passerines. To investigate the relationship between brood size, growth, and steroid hormone production in eastern bluebirds, we cross-fostered nestlings to small, medium, and large broods. Body mass, skeletal size, serum testosterone, and baseline serum corticosterone concentration were measured prior to fledging. Bluebird nestlings raised in large broods weighed less than nestlings in small and medium-sized b... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5112640 Tue, 26 Jul 2011 23:00:00 +0100 5112640 http://www.medworm.com/index.php?rid=5112643&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21802420%26dopt%3DAbstract In conclusion our results demonstrate a CB1 receptor dependent modulation of GnRH system expression rate (both ligands and receptors) in frog diencephalons. In particular, we show that AEA, besides GnRH-I, also acts on GnRH-II expression. PMID: 21802420 [PubMed - as supplied by publisher] (Source: General and Comparative Endocrinology) General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5112643 Fri, 22 Jul 2011 23:00:00 +0100 5112643 http://www.medworm.com/index.php?rid=5112642&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21803044%26dopt%3DAbstract Authors: Sternberg RM, Thoemke KR, Korte JJ, Moen SM, Olson JM, Korte L, Tietge JE, Degitz SJ We used ex vivo and in vivo experiments with Xenopus laevis tadpoles to examine the hypothesis that the set-point for negative feedback on pituitary thyroid-stimulating hormone (TSH) synthesis and secretion by thyroid hormones (THs) increases as metamorphosis progresses to allow for the previously-documented concomitant increase in serum TH concentrations and pituitary TSH mRNA expression during this transformative process. First, pituitaries from climactic tadpoles were cultured for up to 96h to characterize the ability of pituitary explants to synthesize and secrete TSHβ in the absence of hypothalamic and circulating hormones. Next, pituitary explants from tadpoles NF stages 54-66 were expo... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5112642 Thu, 21 Jul 2011 23:00:00 +0100 5112642 http://www.medworm.com/index.php?rid=5112644&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21784075%26dopt%3DAbstract Authors: Kobayashi Y, Chiba H, Mizusawa K, Suzuki N, Cerdá-Reverter JM, Takahashi A The five subtypes of melanocortin receptors (MCRs) mediate the functions of α-melanocyte-stimulating hormone (α-MSH) and adrenocorticotropic hormone (ACTH). In fish, these hormones are involved in pigment dispersion and cortisol release, respectively. α-MSH-related peptides exhibit ACTH-like activity in certain fishes. We recently found that multiple Mcr transcripts are expressed in some cell types in the barfin flounder, which is related to regulation of α-MSH activities. Similar results were also observed for the cortisol-releasing activity of α-MSH-related peptides in the head kidney. The present study was undertaken to assess relationship between the expression of multiply expressed Mcrs and Î... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5112644 Mon, 18 Jul 2011 23:00:00 +0100 5112644 http://www.medworm.com/index.php?rid=5112645&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21781968%26dopt%3DAbstract Authors: Ottaviani E, Malagoli D, Franceschi C The complexity of the anatomical distribution and functions of adipose tissue (AT) has been rarely analyzed in an evolutionary perspective. From yeast to man lipid droplets are stored mainly in the form of triglycerides in order to provide energy during periods when energy demands exceed caloric intake. This simple scenario is in agreement with the recent discovery of a highly conserved family of proteins for fat storage in both unicellular and multicellular organisms. However, the evolutionary history of organs such as the fat body in insects, playing a role in immunity and other functions besides energy storage and thermal insulation, and of differently distributed subtypes of AT in vertebrates is much less clear. These topics still awai... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5112645 Wed, 13 Jul 2011 23:00:00 +0100 5112645 http://www.medworm.com/index.php?rid=5112646&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21767538%26dopt%3DAbstract The objective of this study was to evaluate the effect that the hormonal fluctuations of the reproductive cycle have on the stromal remodeling and the expression and activity of matrix metalloproteinases MMP-2 and -9 in the adult female gerbil prostate. For this, serological, ultrastructural, immunohistochemical and biochemical methods were employed. The results showed that the major stromal alteration coincide with the peak of estradiol, which occurs in estrus, and with the peak of progesterone, occurring during diestrus II. MMP-2 and -9 presented a similar pattern of expression and activity during estrous cycle. The estrus was the phase of greater expression and activity of MMP-2 and -9. On the other hand, in DI and DII, the tissue expression and activity of MMP-2 and -9 was very weak. T... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5112646 Tue, 12 Jul 2011 23:00:00 +0100 5112646 http://www.medworm.com/index.php?rid=5019487&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21741381%26dopt%3DAbstract The objectives of the present studies were to clone and characterize full-length catfish LLP gene, examine tissue expression of LLP mRNA, and determine effects of prolonged fasting and exposure to Edwardsiella ictaluri (E. ictaluri), the bacteria that causes enteric septicemia in catfish, on LLP mRNA expression. Full-length catfish LLP gene was sequenced by genome walking and by 5'- and 3'-RACE. Catfish LLP gene contained three exons with the coding region located in exons 2 and 3. The amino acid sequence of the channel catfish LLP shared very low sequence similarities with leptin of other fish species or the mammalian leptin (24-49%). Using real-time polymerase chain reaction, LLP mRNA expression was detected in various tissues including brain, stomach, spleen, heart, liver, and trunk kid... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5019487 Mon, 27 Jun 2011 23:00:00 +0100 5019487 http://www.medworm.com/index.php?rid=5019493&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21712039%26dopt%3DAbstract We examined the effects of proximity to a road on nestling glucocorticoid activity and growth in the mountain white-crowned sparrow (Zonotrichia leucophrys oriantha). Additionally, we examined several possible indirect factors that may influence nestling corticosterone (CORT) activity secretion in relation to roads. These indirect effects include parental CORT activity, nest-site characteristics, and parental provisioning. And finally, we assessed possible fitness consequences of roads through measures of fledging success. Nestlings near roads had increased CORT activity, elevated at both baseline and stress-induced levels. Surprisingly, these nestlings were also bigger. Generally, greater corticosterone activity is associated with reduced growth. However, the hypothalamic-pituitary-adrena... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5019493 Fri, 24 Jun 2011 23:00:00 +0100 5019493 http://www.medworm.com/index.php?rid=5019492&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21712040%26dopt%3DAbstract Authors: Fanouraki E, Mylonas CC, Papandroulakis N, Pavlidis M The aim of the present study was to examine the species-specific stress response for seven Mediterranean fishes in culture. Also, to evaluate the method of measuring free cortisol concentration in the rearing water as a non-invasive and reliable indicator of stress in marine species, of aquaculture importance. Gilthead sea bream, Sparus aurata (Sparidae); common dentex, Dentex dentex (Sparidae); common Pandora, Pagellus erythrinus (Sparidae); sharpsnout sea bream, Diplodus puntazzo (Sparidae); dusky grouper, Epinephelus marginatus (Serranidae); meagre, Argyrosomus regius (Sciaenidae) and European sea bass, Dicentrarchus labrax (Moronidae) were subjected to identical acute stress (5-6min chasing and 1-1.5min air exposure) un... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5019492 Fri, 24 Jun 2011 23:00:00 +0100 5019492 http://www.medworm.com/index.php?rid=5019490&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21726558%26dopt%3DAbstract Authors: Kersey DC, Wildt DE, Brown JL, Snyder RJ, Huang Y, Monfort SL To better understand the adaptive significance of adrenal glucocorticoid (GC) variation in the giant panda, we assessed patterns of fecal GC excretion over time as well as during estrus, parturient and non-parturient luteal phases, lactation and acyclicity in 17 adult females. Fecal estrogen and GC patterns were positively correlated (P<0.05) in four of five periestrual females (r=0.57-0.92). Among all reproductive states, fecal GC was highest (P<0.05) during periestrus (non-parturient, 495.9±100.7ng/g [mean±SE]; parturient, 654.1±106.5ng/g; P>0.05). Concentrations of GC metabolites were lower (P<0.05) during the later stage of the luteal phase in non-parturient (334.8±24.8ng/g) compared to parturien... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5019490 Fri, 24 Jun 2011 23:00:00 +0100 5019490 http://www.medworm.com/index.php?rid=5019489&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21726559%26dopt%3DAbstract Authors: Wonglapsuwan M, Chotigeat W, Timmons A, McCall K To develop banana prawn (Fenneropenaeus merguiensis) aquaculture, the mechanism of ovarian maturation is under investigation. In a previous study, we reported the RpL10A protein as an ovarian maturation stimulator. To further investigate the function of RpL10A, we turned to the fruit fly (Drosophila melanogaster) to take advantage of the genetic tools available. Here, we elucidate the expression and function of RpL10A in the D. melanogaster ovary. RpL10A is expressed in the cytoplasm of both nurse and follicle cells throughout oogenesis. While shrimp have one RpL10A gene, D. melanogaster has two genes, RpL10Aa and RpL10Ab. RpL10Ab displays more similarity with shrimp RpL10A and was further investigated. RpL10Ab homozygous mutant... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5019489 Fri, 24 Jun 2011 23:00:00 +0100 5019489 http://www.medworm.com/index.php?rid=5019488&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21726560%26dopt%3DAbstract Authors: Caruso MA, Sheridan MA Fish have provided essential information about the structure, biosynthesis, evolution, and function of insulin (INS) as well as about the structure, evolution, and mechanism of action of insulin receptors (IR). INS, insulin-like growth factor (IGF)-1, and IGF-2 share a common ancestor; INS and a single IGF occur in Agnathans, whereas INS and distinct IGF-1 and IGF-2s appear in Chondrichthyes. Some but not all teleost fish possess multiple INS genes, but it is not clear if they arose from a common gene duplication event or from multiple separate gene duplications. INS is produced by the endocrine pancreas of fish as well as by several other tissues, including brain, pituitary, gastrointestinal tract, and adipose tissue. INS regulates various aspects of fe... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5019488 Fri, 24 Jun 2011 23:00:00 +0100 5019488 http://www.medworm.com/index.php?rid=5019491&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21722641%26dopt%3DAbstract This study reports the EcR and RXR sequences from American lobster, a commercially and ecologically important crustacean. We cloned two EcR splice variants, both of which specifically bind ponasterone A, and two RXR variants, both of which enhance binding of ponasterone A to the EcR. Lobster EcR has high affinity for ponasterone A and muristerone and moderately high affinity for the insecticide tebufenozide. Bisphenol A, diethyl phthalate, and two polychlorinated biphenyls (PCB 29 and PCB 30), environmental chemicals shown to interfere with crustacean molting, showed little or no affinity for lobster EcR. These studies establish the molecular basis for investigation of lobster ecdysteroid signaling and signal disruption by environmental chemicals. PMID: 21722641 [PubMed - as supplied b... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5019491 Tue, 21 Jun 2011 23:00:00 +0100 5019491 http://www.medworm.com/index.php?rid=5019494&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21704626%26dopt%3DAbstract Authors: Hildahl J, Sandvik GK, Edvardsen RB, Norberg B, Haug TM, Weltzien FA Gonadotropin releasing hormones (GnRH) are an important part of the brain-pituitary-gonad axis in vertebrates. GnRH binding to its receptors (GnRH-R) stimulates synthesis and release of gonadotropins in the pituitary. GnRH-Rs also mediate other processes in the central nervous system such as reproductive behavior and neuromodulation. As many as five GnRH-R genes have been identified in two teleost fish species, but the function and phylogenetic relationship of these receptors is not fully understood. To gain a better understanding of the functional relationship between multiple GnRH-Rs in an important aquaculture species, the Atlantic cod (Gadus morhua), we identified four GnRH-Rs (gmGnRH-R) by RT-PCR, follow... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5019494 Thu, 16 Jun 2011 23:00:00 +0100 5019494 http://www.medworm.com/index.php?rid=5019499&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21703269%26dopt%3DAbstract Authors: Murase D, Taniuchi S, Takeuchi S, Adachi H, Kansaku N, Okazaki K, Ohkubo T In the present study, we expressed chicken (ch) Pit-1α (chPit-1α) and chPit-1γin vitro to compare the roles of chPit-1s in the transcription of the chicken growth hormone (chGH) gene. Both green fluorescence protein (GFP)-fused chPit-1γ and GFP-fused chPit-1α were localized in the nuclei of COS-7 cells. In a luciferase reporter gene assay, both chPit-1α and chPit-1γ transactivated the chGH promoter, and chPit-1α showed a more potent effect than chPit-1γ. On the other hand, an increase of cellular cAMP induced by forskolin promoted transactivation of the chGH gene with chPit-1α and chPit-1γ to similar extents. These results suggest that chPit-1γ may modulate the basal promoter activity of the... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5019499 Tue, 14 Jun 2011 23:00:00 +0100 5019499 http://www.medworm.com/index.php?rid=5019496&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21703272%26dopt%3DAbstract Authors: Tam JK, Lee LT, Cheng CH, Chow BK Pituitary adenylate cyclase-activating polypeptide (PACAP)-related peptide (PRP) is a peptide encoded with PACAP in the same precursor protein. Non-mammalian PRPs were previously termed growth hormone-releasing hormone (GHRH)-like peptide, and was regarded as the mammalian GHRH homologue in non-mammalian vertebrates until the discovery of authentic GHRH genes in teleosts and amphibians. Although a highly specific receptor for PRP, which is lost in mammals, is present in non-mammals, a clear function of PRP in vertebrates remains unknown. Using goldfish as a model, here we show the expression of PRP and its cognate receptor in the brain-pituitary-gonadal (BPG) axis, thus suggesting a function of goldfish (gf) PRP in regulating reproduction. We ... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5019496 Tue, 14 Jun 2011 23:00:00 +0100 5019496 http://www.medworm.com/index.php?rid=5019500&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21703268%26dopt%3DAbstract In this study, we used liver, muscle, and gill tissue from sexually immature rainbow trout incubated in vitro to evaluate the extrapituitary effects of 17β-estradiol (E2) and testosterone (T) on mRNA and functional expression of growth hormone receptors (GHR), insulin-like growth factors 1 and 2 (IGF-1, IGF-2), and type 1 IGF receptors (IGFR1). E2 significantly decreased steady-state levels of GHR1, GHR2, and IGF-1 mRNAs in liver as well as of GHR1 and GHR2 mRNAs in muscle and of IGF-1 and IGF-2 mRNAs in gill in a time- and concentration-dependent manner. E2 had no effect on levels of IGFR1 mRNAs in muscle or on GHR and IGFR1 mRNAs in gill. Functional expression of GHRs as assessed by (125)I-GH binding capacity was reduced by E2 in liver and muscle; however, E2 did not affect (125)I-IGF-1... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5019500 Mon, 13 Jun 2011 23:00:00 +0100 5019500 http://www.medworm.com/index.php?rid=5019498&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21703270%26dopt%3DAbstract Authors: Marquez AG, Pietri JE, Smithers HM, Nuss A, Antonova Y, Drexler AL, Riehle MA, Brown MR, Luckhart S Insulin-like peptides (ILPs) regulate a multitude of biological processes, including metabolism and immunity to infection, and share similar structural motifs across widely divergent taxa. Insulin/insulin-like growth factor signaling (IIS) pathway elements are similarly conserved. We have shown that IIS regulates reproduction, innate immunity, and lifespan in female Anopheles stephensi, a major mosquito vector of human malaria. To further explore IIS regulation of these processes, we identified genes encoding five ILPs in this species and characterized their expression in tissues. Antisera to ILP homologs in Anopheles gambiae were used to identify cellular sources in An. stephen... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5019498 Mon, 13 Jun 2011 23:00:00 +0100 5019498 http://www.medworm.com/index.php?rid=5019497&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21703271%26dopt%3DAbstract Authors: Taillebois L, Keith P, Valade P, Torres P, Baloche S, Dufour S, Rousseau K After oceanic migration, post-larvae of the amphidromous Sicyopterus lagocephalus recruit to rivers in Reunion Island. As they enter the river mouth, post-larvae undergo many morphological, physiological and behavioural changes. These drastic changes, which allow them to change feeding regime and to colonise the juvenile and adult freshwater habitat, are defined as metamorphosis. The endocrine control of these changes has never been investigated in Gobioid fish. Here, we investigated whether thyroid hormones (TH) influence metamorphosis in recruiting S.lagocephalus. An analytical study was first performed on a cohort of 2400 fish caught at post-larval stage 1 and maintained for 37days after capture in a... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5019497 Mon, 13 Jun 2011 23:00:00 +0100 5019497 http://www.medworm.com/index.php?rid=5019495&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21703273%26dopt%3DAbstract In this study the magnitude of the corticosterone response to capture and confinement was compared between the breeding and postbreeding season in adult male eastern fence lizards, Sceloporus undulatus. Males were captured in both seasons and subjected to the identical stressor of 4h of confinement. Plasma corticosterone levels in response to confinement were significantly lower in the breeding than the postbreeding season. The effect of testosterone on the stress response was tested by experimentally elevating plasma testosterone levels via silastic implants in free-living males during the postbreeding season. Males with experimentally elevated testosterone exhibited significantly weaker corticosterone responses to 1h of confinement than sham-implanted males. Finally the capacity of the a... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=5019495 Mon, 13 Jun 2011 23:00:00 +0100 5019495 http://www.medworm.com/index.php?rid=4972290&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21679713%26dopt%3DAbstract Authors: Pasquier J, Lafont AG, Leprince J, Vaudry H, Rousseau K, Dufour S The kisspeptin system has emerged as one of the main puberty gatekeepers among vertebrates. The European eel (Anguilla anguilla) is a remarkable model due to its phylogenetical position at the basis of teleosts, and its unique life cycle with a blockade of puberty before reproductive migration. We cloned the full-length coding sequence of a kisspeptin receptor (Kissr) in the eel. Comparison of Kissr sequences assigned the eel Kissr to a basal position in a clade including most of the known teleost Kissr, in agreement with the eel phylogenetical position. Eel Kissr tissue distribution was analyzed by quantitative real-time PCR. Eel Kissr was highly expressed in the brain, especially in the telencephalon and di-/m... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=4972290 Mon, 06 Jun 2011 23:00:00 +0100 4972290 http://www.medworm.com/index.php?rid=4972289&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21679714%26dopt%3DAbstract Authors: Ventura T, Rosen O, Sagi A Over the past six decades, a unique crustacean endocrine organ, the androgenic gland (AG), has occupied the minds of groups researching Crustacea the world over. Unlike male sexual differentiation and maintenance of sexual characteristics in other arthropods, in crustaceans these processes are regulated by the unique male AG. Crustaceans present a particular case in which the gametogenic organ (testis) is clearly separated from the organ regulating sex differentiation (the AG), enabling endocrine manipulations. The AG was first discovered in a decapod species and later investigated in detail not only in decapods but also in amphipods and isopods. The key role of the AG in regulating sex differentiation was subsequently validated in a number of repres... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=4972289 Mon, 06 Jun 2011 23:00:00 +0100 4972289 http://www.medworm.com/index.php?rid=4972292&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21664357%26dopt%3DAbstract Authors: Long Q, Zhu X, Wu Y, Feng B, Jin D, Huang J, Lei T, Gan L, Yang Z Disulfide bond formation is a pivotal step in the maturation and release of secretory proteins that is controlled by specific endoplasmic reticulum (ER) resident enzymes. An important element in this process is Ero (ER oxidoreduction), a glycosylated flavoenzyme tightly associated with oxidative protein folding that lacks the known ER retention motifs. ER resident protein 44kDa (ERp44) is an ER resident protein that mediates ERo1 localization in ER and also prevents the secretion of unassembled cargo proteins with unpaired cysteine. These proteins are not only the key participants in the disulfide-bond formation process, but they also control the secretory pathway on both qualitative and quantitative levels. Her... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=4972292 Mon, 30 May 2011 23:00:00 +0100 4972292 http://www.medworm.com/index.php?rid=4972291&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21664358%26dopt%3DAbstract Authors: Guo L, Shi M, Zhang L, Li G, Zhang L, Shao H, Fang P, Ma Y, Li J, Shi Q, Sui Y Seeing that galanin increases animal body weight on the conditions of inhibiting insulin secretion and animals with metabolic disorder of galanin easily suffer from diabetes, we postulate that endogenous galanin is necessary to reduce insulin resistance in adipocytes. To test this hypothesis, we compared four groups of rats to examine whether an increase in galanin secretion stimulated by swimming may reduce insulin resistance. The rats from sedentary and trained drug groups were injected by M35, a galanin antagonist. The rats from trained control and trained drug groups swam after each injection for four weeks. We found that exercise significantly elevated plasma galanin contents and glucose transp... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=4972291 Mon, 30 May 2011 23:00:00 +0100 4972291 http://www.medworm.com/index.php?rid=4972294&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21663742%26dopt%3DAbstract In conclusion, results of the present study suggests that tissue-specific methylation status of PII and chromatin remodeling through histone modifications of PI.1, coincides with the changes in expression of CYP19 gene and thus are the regulatory mechanism controlling its tissue-specific expression and promoter activity during folliculogenesis and luteinization. PMID: 21663742 [PubMed - as supplied by publisher] (Source: General and Comparative Endocrinology) General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=4972294 Sun, 29 May 2011 23:00:00 +0100 4972294 http://www.medworm.com/index.php?rid=4972293&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21663743%26dopt%3DAbstract Authors: Kanda S, Okubo K, Oka Y The pituitary gonadotropins, follicle-stimulating hormone (FSH) and luteinizing hormone (LH), are essential for the control of vertebrate reproduction. Although the molecular structures of these two hormones are well conserved from teleosts to mammals, some studies report differences in their regulatory mechanisms of gene expression between teleosts and tetrapods. In the present study, we examined the molecular evolution of the gonadotropin gene loci in vertebrates and found that there is a syntenic conservation among the teleost fshb and tetrapod fshb and lhb loci. However, the teleost lhb locus has no syntenic homology to either tetrapod lhb or teleost fshb; this fact suggests that an extensive genome-wide rearrangement of the lhb locus, caused by an ... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=4972293 Sun, 29 May 2011 23:00:00 +0100 4972293 http://www.medworm.com/index.php?rid=4924065&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21651912%26dopt%3DAbstract Authors: Hollar AR, Choi J, Grimm AT, Buchholz DR Spadefoot toad species display extreme variation in larval period duration, due in part to evolution of thyroid hormone (TH) physiology. Specifically, desert species with short larval periods have higher tail tissue content of TH and exhibit increased responsiveness to TH. To address the molecular basis of larval period differences, we examined TH receptor (TR) expression across species. Based on the dual function model for the role of TR in development, we hypothesized that desert spadefoot species with short larval periods would have (1) late onset of TR expression prior to the production of endogenous TH and (2) higher TR levels when endogenous TH becomes available. To test these hypotheses, we cloned fragments of TRα and TRβ genes... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=4924065 Sun, 29 May 2011 23:00:00 +0100 4924065 http://www.medworm.com/index.php?rid=4924064&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21658390%26dopt%3DAbstract Authors: Bevelander GS, Guerreiro PM, Spanings T, Flik G In the gilthead sea bream (Sparus auratus) 17β-estradiol (E(2)) plays an important role in the synthesis of vitellogenin. During vitellogenesis, vitellogenin as a nutritional precursor protein is loaded with calcium, which requires elevated plasma calcium levels. This is accomplished via E(2)-dependent processes. Reports have shown that hypercalcemic effects of E(2) are possibly mediated by another hypercalcemic factor, viz. parathyroid hormone related protein (PTHrP). To further investigate the possibility of PTHrP as a mediator of E(2)-induced hypercalcemia, we investigated the local expression levels of the pthrp mRNA and of the gene coding for the PTHrP receptor, PTH1R(pth1r) in two tissues involved in the calcium regulation... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=4924064 Sun, 29 May 2011 23:00:00 +0100 4924064 http://www.medworm.com/index.php?rid=4924071&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21641907%26dopt%3DAbstract Authors: Rodríguez Díaz MA, Candal E, Santos-Durán GN, Adrio F, Rodríguez-Moldes I We studied the organization of Met-enkephalin-containing cells and fibers in the developing preoptic-hypophyseal system of the brown trout (Salmo trutta fario) by immunohistochemistry and determined the relationship of these cells and fibers to the galaninergic and GABAergic systems. Met-enkephalin immunoreactivity was observed in cells in the preoptic area, the hypothalamus and the pituitary of late larvae. In the hypophysis, a few Met-enkephalin-containing cells were present in all divisions of the adenohypophysis, and some immunoreactive fibers were present in the interdigitations of the neural lobe with the proximal pars distalis. Concurrently, GABAergic fibers innervated the anterior and posteri... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=4924071 Thu, 26 May 2011 23:00:00 +0100 4924071 http://www.medworm.com/index.php?rid=4924070&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21641908%26dopt%3DAbstract Authors: Notch EG, Mayer GD A variety of pharmacological agonists, antagonists and selective estrogen receptor modulators (SERM) have been used to better understand the role of specific receptors in various physiologic processes. Despite similar structure and function, less is known about the effect of agonists and antagonists on teleost estrogen receptors and the results of these studies have indicated wide variation among species. The goal of this study was to determine the ability of two human SERMs to modulate activation of three zebrafish estrogen receptor isoforms. Full length cDNA of zebrafish estrogen receptor 1 (esr1), estrogen receptor 2a (esr2a) and estrogen receptor 2b (esr2b) were cloned into expression vectors and transfected into cells that do not endogenously express an... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=4924070 Thu, 26 May 2011 23:00:00 +0100 4924070 http://www.medworm.com/index.php?rid=4924069&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21641909%26dopt%3DAbstract In this study, we systematically surveyed the BIGFLP-producing tissues and stages by means of immunohistochemistry, in situ hybridization and real-time quantitative RT-PCR, showing that BIGFLP is also produced by the neurosecretory cells in the brain, ovariole sheath and testis sheath, in a stage-specific manner. The BIGFLP-producing cells in the brain were identical to the cells that produce bombyxins, insulin-like peptides of B. mori, but the temporal expression patterns of both peptides were totally different. The BIGFLP gene expression in the sheaths of ovariole and testis were induced by ecdysteroid in vitro, similar to the expression in the fat body. A very high BIGFLP immunoreactivity was also found in the pupal nephrocytes, a functional equivalent of the glomerular podocytes in the... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=4924069 Thu, 26 May 2011 23:00:00 +0100 4924069 http://www.medworm.com/index.php?rid=4924066&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21641910%26dopt%3DAbstract This study demonstrates the importance of considering the effects of developmental conditions on the stress response at several scales. PMID: 21641910 [PubMed - as supplied by publisher] (Source: General and Comparative Endocrinology) General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=4924066 Thu, 26 May 2011 23:00:00 +0100 4924066 http://www.medworm.com/index.php?rid=4924072&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21640119%26dopt%3DAbstract Authors: Quillfeldt P, Poisbleau M, Parenteau C, Trouvé C, Demongin L, van Noordwijk HJ, Möstl E Large inter-species differences have been found in yolk corticosterone amounts in avian eggs. While some studies have failed to detect significant amounts of corticosterone, in other species high amounts have been recorded, such as in a recent study of southern rockhopper penguins Eudyptes chrysocome chrysocome. However, attention has been drawn recently to the fact that many antibodies for corticosterone measurement cross-react with other steroids present in the yolk. In particular, progesterone and related substances can occur in yolk in high concentrations, such that also low cross-reactions of corticosterone assays may lead to measurement errors. We thus performed high-performance liq... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=4924072 Mon, 23 May 2011 23:00:00 +0100 4924072 http://www.medworm.com/index.php?rid=4924083&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21624368%26dopt%3DAbstract Authors: Boerjan B, Sas F, Ernst UR, Tobback J, Lemière F, Vandegehuchte M, Janssen CR, Badisco L, Marchal E, Verlinden H, Schoofs L, De Loof A The morphological, physiological and behavioural differences between solitarious and gregarious desert locusts are so pronounced that one could easily mistake the two phases as belonging to different species, if one has no knowledge of the phenomenon of phenotypic plasticity. A number of phase-specific features are hormonally controlled. Juvenile hormone promotes several solitarious features, the green cuticular colour being the most obvious one. The neuropeptide corazonin elicits the dark cuticular colour that is typical for the gregarious phase, as well as particular gregarious behavioural characteristics. However, it had to be concluded, fo... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=4924083 Sun, 22 May 2011 23:00:00 +0100 4924083 http://www.medworm.com/index.php?rid=4924076&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21624369%26dopt%3DAbstract We examined the effects of atrial, B-type, ventricular and C-type natriuretic peptides (ANP, BNP, VNP and CNP1, 3, 4) on cortisol secretion from interrenal tissue in vitro in both freshwater (FW) and seawater (SW)-acclimated eels. We first localized the interrenal and chromaffin cells in the eel head kidney using cell specific markers (cholesterol side-chain cleavage enzyme (P450ssc) and tyrosine hydroxylase (TH), respectively) and established the in vitro incubation system for eel interrenal tissue. Unexpectedly, none of the NPs given alone to the interrenal tissue of FW and SW eels stimulated cortisol secretion. However, ANP and VNP, but not BNP and three CNPs, enhanced the steroidogenic action of ACTH in SW interrenal preparations, while CNP1 and CNP4, but not ANP, BNP, VNP and CNP3, po... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=4924076 Sun, 22 May 2011 23:00:00 +0100 4924076 http://www.medworm.com/index.php?rid=4924074&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21624370%26dopt%3DAbstract Authors: Ninnes CE, Waas JR, Ling N, Nakagawa S, Banks JC, Bell DG, Bright A, Carey PW, Chandler J, Hudson QJ, Ingram JR, Lyall K, Morgan DK, Stevens MI, Wallace J, Möstl E To understand how the social and physical environment influences behaviour, reproduction and survival, studies of underlying hormonal processes are crucial; in particular, interactions between stress and reproductive responses may have critical influences on breeding schedules. Several authors have examined the timing of breeding in relation to environmental stimuli, while others have independently described endocrine profiles. However, few studies have simultaneously measured endocrine profiles, breeding behaviour, and offspring survival across seasons. We measured sex and stress hormone concentrations (oestrogens... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=4924074 Sun, 22 May 2011 23:00:00 +0100 4924074 http://www.medworm.com/index.php?rid=4924091&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21621541%26dopt%3DAbstract Authors: Joss JM The following is a brief description of how lungfish research at Macquarie University began, of the period in which it flourished, and, most recently, of the winding down of the University's involvement with this research. During this latter period, the Australian lungfish in the wild were threatened by the construction of a megadam in their very limited habitat. Fortunately, this was averted in December 2009, after 3years of lobbying the Federal Government. They now await another "Aussie" to make them accessible for further research by Australian and international researchers. PMID: 21621541 [PubMed - as supplied by publisher] (Source: General and Comparative Endocrinology) General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=4924091 Thu, 19 May 2011 23:00:00 +0100 4924091 http://www.medworm.com/index.php?rid=4877241&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21605561%26dopt%3DAbstract Authors: de Almeida FF, Andersson E, Mittelholzer C, Karlsen O, Taranger GL, Schulz RW Pituitary mRNA levels of gonadotropin β-subunits and of their cognate receptors in the testis were studied during puberty in Atlantic cod under normal and experimental photoperiod conditions that suppressed, delayed or accelerated testis maturation. Results are discussed in context with changes in testicular histology and plasma androgen levels, considered as end points of gonadotropic regulation. Up-regulation of fshb was closely associated with the onset of puberty, decreased when spermatogenesis was completed and reached minimum levels after spawning. These results demonstrate, for the first time using an experimental approach, that activation of Fsh-dependent signaling is associated with spermat... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=4877241 Fri, 13 May 2011 23:00:00 +0100 4877241 http://www.medworm.com/index.php?rid=4877248&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21596043%26dopt%3DAbstract Authors: Herring G, Ackerman JT Coloniality in nesting birds represents an important life history strategy for maximizing reproductive success. Birds nesting near the edge of colonies tend to have lower reproductive success than individuals nesting near colony centers, and offspring of edge-nesting parents may be impaired relative to those of central-nesting parents. We used fecal corticosterone metabolites in California gull chicks (Larus californicus) to examine whether colony size or location within the colony influenced a chick's physiological condition. We found that chicks being raised near colony edges had higher fecal corticosterone metabolite concentrations than chicks raised near colony centers, but that colony size (ranging from 150 to 11,554 nests) had no influence on fecal... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=4877248 Mon, 09 May 2011 23:00:00 +0100 4877248 http://www.medworm.com/index.php?rid=4877247&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21596044%26dopt%3DAbstract Authors: Chung JS, Manor R, Sagi A In malacostracan crustaceans, sex differentiation is uniquely regulated by a hormone secreted by the male-specific androgenic gland (AG). An isopod AG hormone was the first to be structurally elucidated and was found to belong to the insulin superfamily of proteins. Recently, it has been found that the AGs of several decapod crustaceans express insulin-like androgenic gland factors (IAGs), whose function is believed to be similar to that of the isopod AG hormone. Here we report the isolation from the blue crab Callinectes sapidus of the full-length cDNA encoding a candidate insulin-like AG hormone, termed Cas-IAG. The predicted protein Cas-IAG was encoded as a precursor consisting of a signal peptide, the B chain, the C peptide, and the A chain in tha... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=4877247 Mon, 09 May 2011 23:00:00 +0100 4877247 http://www.medworm.com/index.php?rid=4877246&cid=s_35585_15_f&fid=35585&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21596045%26dopt%3DAbstract In this study, the spatial-temporal expression of two distinct IGF-IR mRNAs was investigated by real-time RT-PCR. The spatial distribution of two IGF-IR mRNAs in adult tissues is largely overlapped, but they exhibit distinct temporal expression patterns during larval development. A remarkable decrease in IGF-IR-2 mRNA was detected during metamorphosis. In contrast, a significant increase in IGF-IR-1 mRNA was determined from pre-metamorphosis to metamorphic completion. These indicate that they may play different function roles during the flounder metamorphosis. The levels and localization of IGF-IR proteins during larval development were further studied by Western blotting and immunohistochemistry. Immunoreactive IGF-IRs were detected throughout larval development, and the IGF-IR proteins d... General and Comparative Endocrinology journals http://www.medworm.com/rss/comments.php?id=4877246 Mon, 09 May 2011 23:00:00 +0100 4877246