General and comparative endocrinology最新文献

{"title":"Global analysis of ligand-gated ion channel conservation across Platyhelminthes","authors":"Víctor Hugo Caña-Bozada ,&nbsp;Ahmed A.Z. Dawoud ,&nbsp;Ivana Ramos-de la Cruz ,&nbsp;Lizeth C. Flores-Méndez ,&nbsp;Josué Barrera-Redondo ,&nbsp;Jesús Briones-Mendoza ,&nbsp;Luis A. Yañez-Guerra","doi":"10.1016/j.ygcen.2025.114718","DOIUrl":"10.1016/j.ygcen.2025.114718","url":null,"abstract":"<div><div>Ligand-gated ion channels (LGICs) are critical for neurotransmission, mediating responses to neurotransmitters and hormones, and influencing diverse physiological processes. This study identifies and classifies LGICs across Platyhelminthes, with a particular focus on parasitic neodermatans, which impact human and animal health. Using bioinformatics tools, we analyzed LGICs from 41 neodermatan species and expanded our investigation to encompass vertebrates, other invertebrates, and non-bilaterians to trace LGIC evolutionary pathways across Metazoa. We identified 2,269 putative LGICs within neodermatan species, which we classified into the cys-loop, ASIC/Deg/ENaC, iGluR, and P2X families. Our phylogenetic and clustering analyses reveal lineage-specific patterns with distinct evolutionary trajectories for each LGIC family in neodermatans compared to free-living platyhelminths and other taxa. Notably, the ASIC/Deg/ENaC family displayed the greatest degree of neodermatan-specific divergence, while cys-loop and P2X families were more conserved across taxa. To provide insight into their potential physiological roles, we analyzed LGIC expression patterns in <em>Schistosoma mansoni</em>, revealing widespread expression across neuronal and muscle cell types. The distribution of acid-sensing ion channels (ASICs) in both neurons and muscles suggests a role in neuromuscular signalling, while the P2X receptor (Smp_333600) exhibited sex-specific expression, potentially indicating distinct functional roles in males and females. Additionally, several cys-loop acetylcholine and GABA receptors showed differential neuronal and muscle expression, highlighting their likely contributions to cholinergic and inhibitory neurotransmission. These findings underscore the relevance of LGICs in parasite physiology, particularly in neuromuscular and sensory processes, and suggest potential targets for antiparasitic interventions.</div></div>","PeriodicalId":12582,"journal":{"name":"General and comparative endocrinology","volume":"366 ","pages":"Article 114718"},"PeriodicalIF":2.1,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143742767","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Urotensin II in GIFT Nile tilapia (Oreochromis niloticus): CDS cloning, tissue distribution, and in vitro regulation of male reproduction","authors":"Ying Bai,&nbsp;Xusheng Zhang,&nbsp;Xiaozheng Yu,&nbsp;Yingying Lian,&nbsp;Kingwai Lai,&nbsp;Xiaoxia Chen,&nbsp;Wensheng Li,&nbsp;Caiyun Sun","doi":"10.1016/j.ygcen.2025.114720","DOIUrl":"10.1016/j.ygcen.2025.114720","url":null,"abstract":"<div><div>The caudal neurosecretory system (CNSS), present in all jawed vertebrates, except sarcopterygians, is considered a major site of urotensin II (UII) secretion. UII, a 12-amino acid peptide with a conserved hexapeptide ring structure, is also secreted by other tissues and found in sarcopterygians. UII has been associated with endocrine regulation, osmoregulation, and several pathophysiological conditions. In this study, CDS of GIFT Nile tilapia (<em>Oreochromis niloticus</em>) UII (tUII) and its receptors UT1 (tUT1) and UT2 (tUT2) were cloned from the CNSS and cerebellum, respectively. Phylogenetic analysis indicated that tUII, tUT1, and tUT2 shared a high homology with the ones of cichlid species, <em>Haplochromis burtoni</em> and <em>Neolamprologus brichardi</em>. Despite variations in precursor peptide sequences, the core sequence of the mature UII peptide remains highly conserved. tUII was predominantly expressed in the CNSS, while tUT1 and tUT2 were widely distributed in the central nervous system (CNS) and peripheral tissues of male and female tilapia. Functional studies revealed that synthetic tUII significantly activated luciferase activity in HEK293T cells transiently transfected with pNFAT-TA-Luc vectors and tUT1 or tUT2. In vitro studies in male GIFT Nile tilapia showed that tUII stimulated mRNA expression of <em>gnrh1</em>, <em>gnrh2</em>, and <em>gnrh3</em> in a dose-dependent manner by brain fragments, as well as <em>fshβ</em>, <em>lhβ</em>, and <em>gthα</em> by primary culture of pituitary cells. Furthermore, tUII promoted the expression of <em>gnrhr1</em>, <em>gnrhr2</em>, and <em>gnrhr3</em> in pituitary cells and stimulated mRNA levels of <em>fshr</em>, <em>lhr</em>, <em>arα</em>, <em>cyp11b2</em>, and <em>dmrt1</em> in testicular tissue. All these stimulatory effects of tUII on gene expression mentioned above were blocked by the non-selective UT antagonist urantide, suggesting for the first time that the actions of tUII were mediated via tUT1 or tUT2. In addition, tUII could significantly stimulate the secretion of testosterone by testis fragments. Taken together, these results suggest that tUII may play a role in reproductive regulation in male GIFT Nile tilapia.</div></div>","PeriodicalId":12582,"journal":{"name":"General and comparative endocrinology","volume":"367 ","pages":"Article 114720"},"PeriodicalIF":2.1,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143779750","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of stress on profiles of fecal glucocorticoid and androgen metabolites and antler status in marsh deer (Blastocerus dichotomus)","authors":"Laís Jaqueline de Souza ,&nbsp;Eveline dos Santos Zanetti ,&nbsp;José Maurício Barbanti Duarte","doi":"10.1016/j.ygcen.2025.114719","DOIUrl":"10.1016/j.ygcen.2025.114719","url":null,"abstract":"<div><div>The influence of glucocorticoids on reproductive hormones and antler cycles in cervids remains poorly understood, particularly in tropical species. Most Neotropical deer, like the marsh deer (<em>Blastocerus dichotomus</em>), lack a defined breeding season or a clear link between antler stage and reproductive status. Furthermore, conflicting data regarding stress impacts on androgen levels and antler development underscore the need for further research. We evaluated the effects of stress on fecal glucocorticoid metabolites (FGMs), fecal androgen metabolites (FAMs) and antler status in captive marsh deer. Nineteen males underwent a quarantine after being transferred to a new breeding site, with antler status monitored weekly. Daily fecal samples from 17 individuals were analyzed using EIA to measure FAM and FGM concentrations. Among 12 animals with fully developed antlers, nearly 60 % (n = 7) experienced antler casting, an unusual synchrony for this species. A positive correlation was found between FAM and FGM levels (p &lt; 0.001; r = 0.40). We compared FAM and FGM levels between juveniles and adults, as well as among the antler categories. Adults exhibited 1.2-fold higher FGM levels than juveniles, with no differences in FAM levels. Males with hard antlers showed the highest FAM levels, while FGM levels were highest in males with velvet antlers. We hypothesize that intense stress negatively affected antler retention, leading to antler casting. Our findings suggest that stressful stimuli may trigger adrenal secretion of glucocorticoids and androgens, providing insights into the relationship between stress and antler dynamics in marsh deer.</div></div>","PeriodicalId":12582,"journal":{"name":"General and comparative endocrinology","volume":"367 ","pages":"Article 114719"},"PeriodicalIF":2.1,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143779744","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Coordinated regulation of the hypothalamic–pituitary–somatotropic axis in Chinese sea bass (Lateolabrax maculatus) under temperature and salinity changes","authors":"Tianyu Zhou ,&nbsp;Juyan Li ,&nbsp;Junyu Chen ,&nbsp;Wei Lu ,&nbsp;Lingqun Zhang ,&nbsp;Jie Cheng","doi":"10.1016/j.ygcen.2025.114717","DOIUrl":"10.1016/j.ygcen.2025.114717","url":null,"abstract":"<div><div>Hypothalamic–Pituitary–Somatotropic (HPS) axis contains essential endocrine factors and plays diverse roles in the growth of teleost living in dynamic aquatic environments. In this study, 43 HPS axis genes were characterized in Chinese sea bass (<em>Lateolabrax maculatus</em>), the economically important marine fish highly adaptable to a wide range of temperatures and salinities. The phylogeny, conserved domain, molecular evolution and expression of <em>L. maculatus</em> HPS axis genes revealed their evolutionary conservation, with examples of functional divergence in duplication-originated genes (<em>sst1a/1b</em>, <em>igf1ra/1rb</em>). Weighted gene co-expression network analysis (WGCNA) among <em>L. maculatus</em> tissues revealed strong co-expression of HPS genes (<em>sst</em>s, <em>igf1r</em>s, <em>igfbp</em>s) in brains than in livers and muscles, interacting with feeding (<em>cartpt</em>, <em>negr1</em>), metabolism (<em>grik3</em>, <em>drd4</em>), and growth (<em>apba1</em>) functional genes. Under temperature changes, <em>L. maculatus</em> HPS genes were more actively regulated in brains than in livers and muscles, with the hypothalamic and pituitary HPS genes mainly regulated in brains, whereas the peripheral HPS genes were regulated in livers and muscles. WGCNA revealed that HPS axis mainly interacted with stress and feeding activity in brains of <em>L. maculatus</em> under temperature stress, while it interacted with metabolism and growth activity in livers and muscles. Similar co-expression of HPS genes (<em>sstr</em>s, <em>igf1rb</em>s, <em>igfbp</em>s) were with feeding (<em>pik3r4</em>), metabolism (<em>mrps</em>, <em>ndufa12</em>) and growth (<em>sulf2</em>, <em>peli3</em>, <em>apod</em>) functions in brains, indicating that HPS axis could regulate growth through coordinated mediation of the food-intake and energy metabolism in <em>L. maculatus</em> under environmental stress. Our results provided comprehensive understanding about the <em>L. maculatus</em> HPS axis responding to environmental stimuli, which are crucial for the growth regulation and will provide important insights into fast-growing <em>L. maculatus</em> cultivation.</div></div>","PeriodicalId":12582,"journal":{"name":"General and comparative endocrinology","volume":"366 ","pages":"Article 114717"},"PeriodicalIF":2.1,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143725001","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Light/darkness modulation of the hypothalamic-pituitary-ovarian axis in the plains vizcacha, Lagostomus maximus, a seasonal breeding species","authors":"Santiago Elías Charif ,&nbsp;Pablo Ignacio Felipe Inserra ,&nbsp;Federico Martín Villarreal ,&nbsp;Alejandro Raúl Schmidt ,&nbsp;Santiago Andrés Cortasa ,&nbsp;Sofía Proietto ,&nbsp;María Clara Corso ,&nbsp;Micaela Inés Llanos Dumont ,&nbsp;Noelia Paula Di Giorgio ,&nbsp;Julia Halperin ,&nbsp;Alfredo Daniel Vitullo ,&nbsp;Verónica Berta Dorfman","doi":"10.1016/j.ygcen.2025.114714","DOIUrl":"10.1016/j.ygcen.2025.114714","url":null,"abstract":"<div><div>Photoperiod is the main environmental signal that affects animal behavior and reproduction. Light stimulus is traduced by a neural pathway that modulates pineal gland melatonin release, which synchronizes physiologic functions with day duration, highly influencing seasonal reproduction. The plains vizcacha <em>(Lagostomus maximus)</em> is a Hystricomorph rodent with seasonal reproduction that inhabits the Neotropic in South America. The aim of this work was to elucidate the effect of light/darkness exposition on the reproductive hypothalamic-pituitary-ovarian (HPO) axis in the female plains vizcacha. During 15 days, animals were subjected to different light/darkness regimens (Control group, CTL: 12:12 h dark:light; Darkness group, DARK: continuous darkness; Light group, LIGHT: continuous light). The melatoninergic system and reproductive hormones were evaluated. Plasma melatonin levels significantly decreased in DARK whereas both melatonin receptors (MT₁ and MT₂) expression significantly increased in the hypothalamus and decreased in the pituitary gland, and only MT₁ expression increased in the ovaries. Continuous light did not induce significant variations in melatonin levels related to CTL, however, MTs expression changed at pituitary and ovary levels. Strikingly, both light/darkness regimens increased reproductive hormone expression. While darkness induced hypothalamic gonadotropin-releasing hormone (GnRH) expression and estradiol (E₂) secretion, light increased LH and progesterone (P₄) secretion. In conclusion, light availability may impact the reproductive axis of plains vizcacha inducing hormonal changes, with an organ-specific response, and sustaining HPO axis activity, thus ensuring reproduction. Environmental light and darkness, their availability and exposure length, could synchronize the reproductive axis in seasonal breeding species like the plains vizcacha.</div><div>New &amp; Noteworthy: Hypothalamic, pituitary, and ovarian variations were induced by continuous light or darkness in the plains vizcacha. Plasma melatonin decreased by continuous darkness-inducing hypothalamic, pituitary, and ovarian melatonin receptors variations. Fifteen days of continuous darkness induced GnRH, LH, and estradiol secretion, while 15 days of continuous light induced LH and P₄ secretion. Environmental light/darkness would synchronize the reproductive axis in seasonal breeding species like the plains vizcacha.</div></div>","PeriodicalId":12582,"journal":{"name":"General and comparative endocrinology","volume":"366 ","pages":"Article 114714"},"PeriodicalIF":2.1,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143704846","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Identification and expression of nuclear receptor genes during nutritive phagocyte development in sea urchin Mesocentrotus nudus gonads","authors":"Kazuhiro Ura ,&nbsp;Shiori Tsue ,&nbsp;Takushi Sato ,&nbsp;Seishi Hagihara ,&nbsp;Mizuha Satoh ,&nbsp;Ichiro Higuchi ,&nbsp;Heng Wang ,&nbsp;Osamu Nishimiya ,&nbsp;Shigeho Ijiri ,&nbsp;Yasuaki Takagi","doi":"10.1016/j.ygcen.2025.114715","DOIUrl":"10.1016/j.ygcen.2025.114715","url":null,"abstract":"<div><div>The role of the endocrine system during synthesis of the nutrients (e.g., proteins, lipids, polysaccharides) in the gonad in sea urchins is imperfectly understood. We identify genes encoding nuclear receptors (NRs) involved in the development of nutritive phagocytes of the sea urchin <em>Mesocentrotus nudus</em>, and investigate their gene expression patterns during this time. RNA-seq analysis was performed on immature gonads using a next-generation sequencer. A total of 7,651,421 quality-controlled reads obtained using an Ion PGM sequencer were assembled into 175,092 contigs. BLASTn analysis identified 20 <em>NR</em> genes potentially involved in the development of nutritive phagocytes. Expression analyses revealed levels of four <em>NR</em> genes to increase during the development of nutritive phagocytes. These results indicate that these 20 <em>NR</em> genes have physiological functions in gonadal growth, and that 4 <em>NR</em> genes mainly control the expression of genes involved in the synthesis and metabolism of proteins, lipids, and polysaccharides during cellular proliferation in sea urchin gonads.</div></div>","PeriodicalId":12582,"journal":{"name":"General and comparative endocrinology","volume":"366 ","pages":"Article 114715"},"PeriodicalIF":2.1,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143725000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Identification and characterization of neuropeptides in sea urchin Strongylocentrotus intermedius","authors":"Qianqian Li ,&nbsp;Meiwei Zhang ,&nbsp;Kun Liu ,&nbsp;Mengqiang Yuan ,&nbsp;Weizhong Wang ,&nbsp;Dong Xu ,&nbsp;Deyang Tian ,&nbsp;Xiaotong Wang","doi":"10.1016/j.ygcen.2025.114716","DOIUrl":"10.1016/j.ygcen.2025.114716","url":null,"abstract":"<div><div>Neuropeptides play essential roles in regulation of feeding, reproduction and behavior in echinoderms. But the neuropeptide function has not been explored extensively in sea urchins. The tube feet contain part of the peripheral nervous system in echinoids, comprising both neurosensory and neuromuscular components. In this study, we sequenced transcriptome of <em>Strongylocentrotus intermedius</em> tube feet and identified 26 neuropeptide precursor transcripts, including ANpeptide, bursicons, calcitonin, corazonin, gonadotropin-releasing hormone (GnRH), glycoprotein-type hormones (GPA &amp; GPB), insulin-related peptides (dilp7 &amp; octinsulin), luqin, NGFFFamide, prolactin-releasing peptide/short neuropeptide F (PrRP/sNPF), orexin, pedal peptides, SALMFamides, somatostatin/allatostatin-C (SS1 &amp; SS2), thyrotropin-releasing hormone (TRH), and vasopressin-oxytocin. In addition, we further compared the expression levels of neuropeptide precursors between red and white tube feet, and found 3 neuropeptides (bursicon β, octinsulin and luqin) had higher expression in red tube feet, potentially related to pigmentation or other pigment-related functions. We also observed ultrastructure of tube feet by transmission electron microscopy (TEM) and found large amount of muscle fibers, nerve plexus and vesicles in tube feet. Neuropeptides might play roles in these structures of tube feet. Our study represents the first identification of neuropeptides in tube feet of <em>S. intermedius</em>, and will contribute to a complete understanding on the roles of various neuropeptides in sea urchin echinoderms.</div></div>","PeriodicalId":12582,"journal":{"name":"General and comparative endocrinology","volume":"366 ","pages":"Article 114716"},"PeriodicalIF":2.1,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143700236","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Temperature modulates 17β-estradiol regulation of oogenesis protein expression in the liver of the eurythermal pupfish Cyprinodon nevadensis","authors":"Sean C. Lema,&nbsp;Kseniya A. Krayeva,&nbsp;Zoey A. Dale,&nbsp;Teresa E. Guerre","doi":"10.1016/j.ygcen.2025.114707","DOIUrl":"10.1016/j.ygcen.2025.114707","url":null,"abstract":"<div><div>Female fish experiencing atypically high or prolonged elevations in temperature during oogenesis can suffer impaired oocyte development with fewer or smaller eggs, eggs with reduced yolk content or thinner envelopes, and lower egg viability. These changes in oocyte quality and quantity are in part caused by diminished liver synthesis of egg yolk (vitellogenin, Vtg) and egg envelope (choriogenin) proteins at anomalously high temperatures. Those declines in liver Vtg and choriogenin production are commonly paralleled by reduced blood concentrations of 17β-estradiol (E₂). However, it is unclear whether declines in liver vitellogenin and choriogenin production at elevated temperatures result solely from lower circulating E₂ or if other aspects of E₂ signaling are also altered to diminish liver synthesis of oogenesis proteins. In this study, adult female Amargosa River pupfish (<em>Cyprinodon nevadensis amargosae</em>), a species with asynchronous follicular development, were maintained at 20 °C, 28 °C, or 36 °C and then administered E₂ or vehicle solution. Ovarian gonadosomatic index (GSI) values and plasma E₂ were lower in females at 36 °C compared to those at cooler temperatures. Females at 36 °C also had reduced plasma Vtg protein, lower liver abundances for mRNAs encoding vitellogenin genes (<em>vtgAa</em>, <em>vtgAb</em>, <em>vtgc</em>), choriogenin genes (<em>cgh, cghm, cgl</em>), and estrogen receptor α (<em>esr1</em>). Supplemental E₂ increased plasma E₂ in females at all temperatures, but only upregulated liver vitellogenin and choriogenin mRNAs at 36 °C, despite E₂ upregulation of hepatic <em>esr1</em> receptor transcripts at all temperatures. Females at 36 °C also exhibited higher liver mRNA abundances for sex hormone-binding globulin (<em>shbg</em>) and cytochrome P450 family 1 subfamily A member 1 (<em>cyp1a1</em>), an estrogen-metabolizing monooxygenase enzyme that converts E₂ to 2-hydroxyestradiol. Together, these findings indicate elevated temperatures diminish E₂ stimulation of liver Vtg and choriogenin expression in pupfish via effects on several aspects of E₂ signaling including circulating E₂ concentrations and liver <em>esr1</em> expression as well as <em>shbg</em> and <em>cyp1a1</em> expression, which may result in changes to free:bound E₂ and the rate of hepatic E₂ inactivation. These results also demonstrate that E₂ replacement can help compensate for high temperature-induced declines in hepatic oogenesis gene expression in female pupfish.</div></div>","PeriodicalId":12582,"journal":{"name":"General and comparative endocrinology","volume":"365 ","pages":"Article 114707"},"PeriodicalIF":2.1,"publicationDate":"2025-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143643589","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Post-lactation mass recovery and metabolic hormone dynamics in adult female Weddell seals","authors":"Amy L. Kirkham ,&nbsp;Julie P. Avery ,&nbsp;Roxanne S. Beltran ,&nbsp;Jennifer M. Burns","doi":"10.1016/j.ygcen.2025.114706","DOIUrl":"10.1016/j.ygcen.2025.114706","url":null,"abstract":"<div><div>Weddell seal (<em>Leptonychotes weddellii</em>) females lose substantial body mass across an intensive, nutritionally restricted lactation period and then must rapidly recover mass during the short Antarctic summer. In this study, we examined endocrine dynamics associated with mass loss across lactation and subsequent realimentation in Weddell seals, comparing patterns between seals that recently gave birth and demographically similar non-reproductive females (skip females) in McMurdo Sound, Antarctica. Postpartum seals near weaning (∼35 days postpartum, n = 64) and skip females (n = 32) were handled during early austral summer (November/December) and rehandled in late summer (January/February). Body mass, body composition (% lipid), and a suite of metabolic hormones (growth hormone (GH), insulin-like growth factor (IGF)-I, cortisol, total thyroxine (tT₄), free thyroxine (fT₄), and total triiodothyronine (tT₃) and IGF binding protein (IGFBP)-2 and −3) were measured. Postpartum seals gained mass after weaning (0.98 ± 0.56 kg·day⁻¹ (mean ± SD)), primarily as lean tissue rather than lipid, while their serum concentrations of tT₄ and fT₄, IGF-I, and cortisol increased. Their circulating GH and IGFBP-2 concentrations decreased and correlated negatively with mass. Skip females had greater body masses and lipid stores than postpartum seals at the end of the lactation period in early summer, but they lost mass (−1.03 ± 0.35 kg·day⁻¹) and lipid stores over summer while their serum cortisol concentrations increased. Overall, body mass and composition of postpartum and skip females converged across summer. This convergence, likely driven in large part by contrasting endocrine profiles between the groups, may allow female Weddell seals to reach an advantageous seasonal body mass “set point” by onset of winter.</div></div>","PeriodicalId":12582,"journal":{"name":"General and comparative endocrinology","volume":"365 ","pages":"Article 114706"},"PeriodicalIF":2.1,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143614578","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cortisol production by interrenal cells in rainbow trout (Oncorhynchus mykiss) is stimulated by 5-HT4 receptor activation","authors":"Michael Tea,&nbsp;Laurence E. Dionne-Wilson,&nbsp;Marie-Ève Bélair-Bambrick,&nbsp;Kathleen M. Gilmour","doi":"10.1016/j.ygcen.2025.114694","DOIUrl":"10.1016/j.ygcen.2025.114694","url":null,"abstract":"<div><div>Although serotonin (5-HT) can stimulate the hypothalamic-pituitary-interrenal (HPI) axis in fishes, the sites of 5-HT action and the receptor subtypes involved remain unclear. Therefore, the present study identified potential sites of 5-HT action within the HPI axis of rainbow trout, <em>Oncorhynchus mykiss</em>, and examined which of three 5-HT receptor subtypes mediated effects of 5-HT on cortisol production. Expression of the receptors <em>5htr1a</em>, <em>5htr2</em> and <em>5htr4</em> was detected at all three levels of the HPI axis, with significantly higher transcript abundance in the preoptic area (POA) of the brain than in the pituitary or head kidney. Administration of 300nmol kg⁻¹ 5-HT, but not 30nmol kg⁻¹, to cannulated rainbow trout significantly increased circulating cortisol. Despite this cortisol response, no specific effects of 5-HT administration on POA transcript abundance of corticotropin-releasing factor (<em>crf</em>) or circulating adrenocorticotropic hormone (ACTH) concentrations were detected. To assess the direct actions of 5-HT on cortisol production, head kidney tissue was incubated <em>in vitro</em> with 5-HT or selective 5-HT receptor agonists. Neither the 5-HT_1A receptor agonist 8-hydroxy-2-(di-<em>n</em>-propylamino)-tetralin (8-OH-DPAT) nor the 5-HT₂ receptor agonist α-methyl-5-hydroxytryptamine maleate (α −methyl 5-HT) stimulated cortisol production. However, head kidney cortisol production was significantly increased by the 5-HT₄ receptor agonist cisapride, an effect that was eliminated when tissue was incubated with a combination of cisapride and the 5-HT₄ receptor antagonist GR125487. Collectively, these data support a role for 5-HT in HPI axis activation in rainbow trout, and suggest that effects of 5-HT in the head kidney are mediated by the 5-HT₄ receptor.</div></div>","PeriodicalId":12582,"journal":{"name":"General and comparative endocrinology","volume":"364 ","pages":"Article 114694"},"PeriodicalIF":2.1,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143515435","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}