General and comparative endocrinology最新文献

{"title":"Testosterone concentration coincides with distance travelled in the free-ranging male Saharan sand-viper, Cerastes vipera","authors":"J. Sivan ,&nbsp;A.A. Degen ,&nbsp;S.J.A. Horesh ,&nbsp;I. Tesler ,&nbsp;S. Hadad ,&nbsp;H. Boni ,&nbsp;M. Kam","doi":"10.1016/j.ygcen.2025.114775","DOIUrl":"10.1016/j.ygcen.2025.114775","url":null,"abstract":"<div><div>Testosterone levels have been linked to reproduction and locomotor activities in vertebrates and even to some invertebrates. However, the relationship between testosterone concentration and daily distance travelled (DDT) in a free-ranging reptile has not been tested. The aim of this study was to fill this gap. Seasonal plasma testosterone concentration in the free-ranging male Saharan sand viper, <em>Cerastes vipera</em>, was reported to be bimodal: a large peak in spring during spermatogenesis and mating, and a small peak in autumn, during spermatogenesis but without mating prior to hibernation. We hypothesized that DDT would be bimodal as well, the pattern coinciding with testosterone concentration. To test this hypothesis, we measured monthly DDT in free-ranging <em>C. vipera</em> of the same population at the same site, and compared the pattern with that of plasma testosterone concentrations reported earlier. A bimodal pattern in DDT was observed that coincided with testosterone concentration, and, therefore, our hypothesis was supported. This is the first study demonstrating a link between plasma testosterone concentration and DDT in a free-ranging animal; however, the link is correlational as there was no manipulation and cannot be attributed to a casual effect. Further studies are warranted to clarify the relationship between testosterone level and DDT.</div></div>","PeriodicalId":12582,"journal":{"name":"General and comparative endocrinology","volume":"371 ","pages":"Article 114775"},"PeriodicalIF":2.1,"publicationDate":"2025-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144517919","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":"Regulation of the neuroendocrine stress axis in response to ammonia exposure in rainbow trout: Pharmacological and transcriptional evidence implicating serotonin and multiple hypophysiotropic peptides","authors":"Mauro Chivite-Alcalde ,&nbsp;Brett M. Culbert ,&nbsp;Shayla Larson-Hossack ,&nbsp;Jesús M. Míguez ,&nbsp;Nicholas J. Bernier","doi":"10.1016/j.ygcen.2025.114773","DOIUrl":"10.1016/j.ygcen.2025.114773","url":null,"abstract":"<div><div>Ammonia is neurotoxic and exposure to high environmental ammonia (HEA) activates the hypothalamic-pituitary-interrenal (HPI) axis in teleosts. To gain insight into the neural factors that regulate the HPI axis in response to this environmental stressor, as well as elucidate potential interactions between these factors, we exposed rainbow trout to one of three ammonia levels (0, 650, 1000 μM NH₄Cl) for 24 or 96 h and assessed the gene expression and circulating levels of key determinants of HPI axis activity. In parallel with circulating ammonia concentrations, plasma cortisol levels increased dose-dependently after 24 h of HEA exposure and partially recovered after 96 h. HEA exposure also elicited dose-, time-, and brain region-specific changes in components of the central serotonergic (5-HTergic; <em>tph2, htr1aa, htr1b, htr2c</em>), corticotropin-releasing factor (<em>crfb</em>), arginine vasotocin (<em>avt, avtr1a, avtr2</em>), and isotocin (<em>it, itr</em>) signaling systems. Moreover, while intraperitoneal injections of 5-HT_1B and 5-HT_2C receptor antagonists reduced basal cortisol levels, treatment with 5-HT_1A and 5-HT_2C receptor antagonists blocked the increase in plasma cortisol elicited by HEA. Finally, treatment with specific 5-HT receptor antagonists blunted the HEA-induced increases in brain preoptic area <em>crfb</em>, <em>avt</em>, and <em>it</em> expression. These findings implicate 5-HT and multiple peptidergic systems in the hypophysiotropic regulation of the HPI axis in response to HEA exposure and provide novel insight into the multifactorial neural circuitry mediating the neuroendocrine stress response in fishes.</div></div>","PeriodicalId":12582,"journal":{"name":"General and comparative endocrinology","volume":"371 ","pages":"Article 114773"},"PeriodicalIF":2.1,"publicationDate":"2025-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144514398","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":"Early development of the glucocorticoid stress response in dyeing poison frog tadpoles","authors":"Lisa L. Surber-Cunningham ,&nbsp;Lucas S. Jimenez ,&nbsp;Lauren W. Mobo ,&nbsp;Sarah E. Westrick ,&nbsp;Eva K. Fischer","doi":"10.1016/j.ygcen.2025.114774","DOIUrl":"10.1016/j.ygcen.2025.114774","url":null,"abstract":"<div><div>In vertebrates, the glucocorticoid “stress” response (corticosterone or cortisol) through the hypothalamic–pituitary–adrenal (HPA) axis influences many essential functions, including behavior, metabolism, immunity, and ontogenetic transitions. During development, stress responses can be adaptive if they facilitate antipredator behavior and modulate developmental speed to adjust to environmental conditions; however, these same responses can be maladaptive when energetic costs become too high and developmental speed trades-off with size and health at maturity. Thus, the timing of HPA-axis development may be aligned with specific developmental challenges and opportunities presented by a species’ life history strategy. In anurans (frogs and toads), corticosterone plays critical roles in development and behavior, and concentrations can fluctuate in response to environmental stressors. Given the role of corticosterone in ontogenetic changes and behaviors, we studied the development of the glucocorticoid stress response in tadpoles of the dyeing poison frog (<em>Dendrobates tinctorius</em>), a species with a unique life history that includes transport to water after hatching on land and aggressive and cannibalistic behavior. We measured the excretion rate and whole-body concentration of corticosterone and the corticosterone response to adrenocorticotropic hormone (ACTH) in free-swimming tadpoles after transport and throughout metamorphosis. We found no significant differences across development in excretion rates or whole-body concentration of corticosterone, nor corticosterone response to ACTH, indicating that that the glucocorticoid response develops early in ontogeny. This pattern differs from those in other species, suggesting the unique ecological pressures faced by <em>D. tinctorius</em> have shaped the development of the glucocorticoid stress response in this species. More broadly, this study illustrates how life history strategies and tradeoffs impact the timing of the development of stress responsivity.</div></div>","PeriodicalId":12582,"journal":{"name":"General and comparative endocrinology","volume":"371 ","pages":"Article 114774"},"PeriodicalIF":2.1,"publicationDate":"2025-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144517918","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":"Multifaceted role and regulation of neuropeptide Y in the ovary of wall lizard, Hemidactylus flaviviridis","authors":"Vishesh Chauhan ,&nbsp;Umesh Rai ,&nbsp;Mamta Tripathy ,&nbsp;Sunil Kumar","doi":"10.1016/j.ygcen.2025.114772","DOIUrl":"10.1016/j.ygcen.2025.114772","url":null,"abstract":"<div><div>The role of neuropeptide Y (NPY) in regulating ovarian functions has primarily been studied in mammals, while it remains meagrely explored in non-mammalian vertebrates. Our study is the first to report ovarian expression of <em>npy</em> and its receptor, <em>npyr,</em> in a reptile, <em>Hemidactylus flaviviridis</em>. Quantitative real-time PCR analysis demonstrated high expression of <em>npy/npyr</em> during early and late recrudescence, while significantly low levels were noted during regression. The study also examined role of NPY in modulating lizard ovarian functions, wherein <em>in vitro</em> treatment of recrudescent ovaries with NPY increased the mRNA expression of anti-apoptotic gene B-cell lymphoma 2 (<em>bcl 2</em>), and suppressed pro-apoptotic gene cysteine-aspartic acid protease-3 (<em>caspase 3</em>). NPY also stimulated cell proliferation/differentiation markers; stem cell factor (<em>scf</em>)<em>,</em> receptor tyrosine kinase (<em>c-kit</em>), proliferating cell nuclear antigen (<em>pcna</em>), growth differentiation factor-9 (<em>gdf-9</em>)<em>,</em> bone morphogenetic protein-15 (<em>bmp-15</em>), as well as gonadotropin and sex steroid receptors, follicle stimulating hormone receptor (<em>fshr</em>)<em>,</em> estrogen receptor α, β (<em>er-α, er-β</em>), and progesterone receptor (<em>pr</em>). Also, NPY influenced ovarian steroidogenesis by upregulating steroidogenic acute regulatory protein (<em>star</em>) and cytochrome P450a family 19 (<em>cyp19</em>) mRNA expression. However, steroid estimation by ELISA indicates NPY-mediated differential modulation of steroidogenesis as progesterone production was elevated, while estradiol production was inhibited. Further, ovarian <em>npy/npyr</em> was differentially regulated by gonadotropin, sex steroids, neuropeptides, and adipokines. Expression of ligand and receptor was stimulated by 5α-dihydrotestosterone (DHT), 17β-estradiol (E₂), kisspeptin, leptin, and nesfatin-1 but inhibited by follicle stimulating hormone (FSH) and substance P. Taken together, present study provides a comprehensive picture of ovarian <em>npy/npyr</em> in wall lizard.</div></div>","PeriodicalId":12582,"journal":{"name":"General and comparative endocrinology","volume":"371 ","pages":"Article 114772"},"PeriodicalIF":2.1,"publicationDate":"2025-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144340004","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":"Repeated exogenous hormone administration decreases sperm quantity and quality in threatened frog species (Litoria aurea)","authors":"Shalinie Navaratne,&nbsp;Venice Chan,&nbsp;Amanda Poh,&nbsp;Prabhath Meegamage,&nbsp;Laura A Brannelly","doi":"10.1016/j.ygcen.2025.114771","DOIUrl":"10.1016/j.ygcen.2025.114771","url":null,"abstract":"<div><div>Assisted reproductive technologies are important for protecting threatened amphibian species globally. These technologies can overcome amphibian breeding failure and improve threatened species management and research quality in the fields of reproductive biology and ecology. One assisted reproductive technology is inducing spermiation using exogenous hormone injections. However, the impacts of repeatedly administering exogenous hormones on sperm quality and quantity remain poorly understood. In this study we repeatedly administered an exogenous hormone — human chorionic gonadotropin — in the threatened Australian frog species, <em>Litoria aurea</em>. We analysed sperm quantity and quality over 3–4 hormonal administrations at biweekly, weekly, and fortnightly frequencies (n = 6 for each group). Sperm quality and quantity were assessed at three timepoints over a 6-hour period following each hormonal administration (hours 2, 4, and 6 post-injection). We found that repeated administrations significantly reduced sperm quantity and quality via reduced concentration, volume, total sperm counts, and viability. With repeated administrations, the timing of sperm release varied: after only one administration, sperm was released equivalently in hours 2, 4 and 6 post-injection, whereas after several administrations, sperm release was delayed such that 6 hr post-injection produced higher quantity and quality sperm. Overall, our results demonstrate that repeated hormonal administration of male <em>L. aurea</em> reduces sperm quantity and quality, and individuals will need substantial time to regenerate sperm between administrations.</div></div>","PeriodicalId":12582,"journal":{"name":"General and comparative endocrinology","volume":"370 ","pages":"Article 114771"},"PeriodicalIF":2.1,"publicationDate":"2025-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144336453","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":"Age-related changes in fecal adrenal androgen levels in hylobatids","authors":"Emilee N. Hart ,&nbsp;Susan Margulis ,&nbsp;Rafaela S.C. Takeshita","doi":"10.1016/j.ygcen.2025.114766","DOIUrl":"10.1016/j.ygcen.2025.114766","url":null,"abstract":"<div><div>Adrenarche, or the postnatal activation of the adrenal gland, is a phenomenon exclusive to some primates that is evidenced by high levels of the hormones dehydroepiandrosterone (DHEA) and its sulfated form (DHEAS), independent of the onset of puberty. Within primates, two patterns of adrenal secretions occur: a prepubertal increase in DHEAS levels (adrenarche) that has been reported in humans and great apes, and a continuous postnatal decline on DHEAS levels with age, observed in cercopithecines (e.g., macaques and baboons). Our research seeks to determine the pattern of DHEAS secretion during hylobatid development. DHEAS was measured by enzyme immunoassay in cross-sectional fecal samples from 35 female and 29 male zoo-housed hylobatids (<em>Hylobates, Nomascus, Symphalangus</em>) ranging from age 1 to 54 years. Additionally, we measured longitudinal fecal samples from 7 female hylobatids under human care (6 <em>Nomascus,</em> 1 <em>Hoolock</em>). Our study tested the effects of age, sex, and genus on fecal DHEAS levels using generalized linear mixed-effects models. The models were separated by genus and showed that age was positively correlated with a prepubertal increase in fecal DHEAS across all genera, indicating that the hylobatids exhibit delayed adrenarche. A significant effect of sex was only identified in the <em>Symphalangus</em> model. Results from adult and old hylobatids did not exhibit decreasing DHEAS associated with adrenal senescence, which is characteristic of humans and other primates. The evidence of a delayed DHEAS increase observed across all hylobatid genera suggests a shared developmental characteristic among all ape species.</div></div>","PeriodicalId":12582,"journal":{"name":"General and comparative endocrinology","volume":"370 ","pages":"Article 114766"},"PeriodicalIF":2.1,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144291650","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":"Asprosin modulates female reproductive functions in teleosts: An in vitro study in Channa punctata","authors":"Priyanka Sathoria ,&nbsp;Anju Shrivastava ,&nbsp;Umesh Rai ,&nbsp;Brototi Roy","doi":"10.1016/j.ygcen.2025.114770","DOIUrl":"10.1016/j.ygcen.2025.114770","url":null,"abstract":"<div><div>Asprosin regulates various aspects of physiology in mammals including reproduction. It is reported to profoundly affect both male and female reproductive functions including gametogenesis and steroidogenesis. Asprosin is the cleaved product of a profibrillin protein encoded by the <em>fbn1</em> gene. For the first time in non-mammalian vertebrates, our group demonstrated the ubiquitous expression of <em>fbn1</em> and characterized asprosin protein <em>in silico</em> in teleost <em>Channa punctata</em> commonly known as spotted snakehead (ss). Based on the prominent expression of the <em>fbn1</em> gene and the reproductive phase-dependent temporal expression of <em>fbn1</em> in the ovary of <em>C. punctata</em>, we hypothesized the regulatory role of asprosin in female reproduction similar to that reported in mammals. <em>In vitro</em> studies confirmed the effect of asprosin on the oogenesis and steroidogenesis in <em>C. punctata</em>. Asprosin significantly enhanced the expression of genes crucial for oogenesis such as <em>pcna</em> and <em>gdf9</em>. It also increased the transcription of gonadotropin receptors and sex steroid receptor genes. In addition to this, asprosin accentuated the expression of steroidogenic markers such as <em>star</em> and <em>cyp17a1</em> along with 17α, 20β dihydroxy-progesterone levels. We also measured the levels of the second messenger cAMP in ovaries exposed to asprosin to explore the probability of GPCRs as asprosin receptors. However, asprosin could not alter the cAMP levels indicating that, in the ovary of teleosts, receptors other than GPCRs might be involved in transducing asprosin action. Thus, the present study in elucidates the important role of asprosin in modulating the ovarian functions in <em>C. punctata</em>.</div></div>","PeriodicalId":12582,"journal":{"name":"General and comparative endocrinology","volume":"370 ","pages":"Article 114770"},"PeriodicalIF":2.1,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144281111","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":"Relationships between ambient temperature and diurnal variation in physiological responses to acute handling and restraint stress in the house sparrow, Passer domesticus","authors":"Pierre Deviche ,&nbsp;Sarah E. Polekoff ,&nbsp;Ondi L. Crino ,&nbsp;Justin R. Eastwood ,&nbsp;Simon C. Griffith ,&nbsp;Katherine L. Buchanan","doi":"10.1016/j.ygcen.2025.114767","DOIUrl":"10.1016/j.ygcen.2025.114767","url":null,"abstract":"<div><div>Climate change is altering the frequency and intensity of environmental extremes, and the diurnal rates of environmental change. The daily reaction norms of wild animals show spatial and temporal plasticity to allow appropriate physiological responses to predictable environmental challenges, but these responses have rarely been quantified in wild birds. We addressed this by determining whether physiological stress indices (corticosterone [CORT], glucose [GLU], and circulating heat shock proteins [Hsp]) vary with ambient temperature (T_a) or time of day across a 6⁰ latitudinal gradient (32⁰–38⁰ S). We sampled house sparrows, <em>Passer domesticus</em>, at three locations with varying daily rates of T_a increases in 2015 and in 2019–2020 to determine whether physiological responses to capture and handling stress change diurnally. As predicted, plasma CORT and GLU increased during stress. Baseline CORT and GLU levels did not change during the day, but the amplitude of plasma CORT increase (delta CORT) in response to capture decreased as T_a increased, as was the case for GLU, in birds with initially high baseline CORT. Neither baseline nor stress-related plasma CORT or GLU differed consistently across sampling locations. Heat-shock cognate 70 (Hsc70) and heat-shock protein 90α (Hsp90) showed clear temporal dynamics across the day. Thus, the reaction norms of heat shock proteins are temporally plastic during the day and in response to daily T_a changes, as are the reaction norms of CORT and GLU in response to acute stress. However, the study provides little evidence for such plasticity in reaction norms as a function of average local thermal conditions.</div></div>","PeriodicalId":12582,"journal":{"name":"General and comparative endocrinology","volume":"370 ","pages":"Article 114767"},"PeriodicalIF":2.1,"publicationDate":"2025-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144281110","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":"Amino acid residues critical to cAMP signaling by V2a-type vasopressin/vasotocin receptor: an evolutionary perspective","authors":"Yoko Yamaguchi","doi":"10.1016/j.ygcen.2025.114758","DOIUrl":"10.1016/j.ygcen.2025.114758","url":null,"abstract":"<div><div>Vasopressin (VP) and its non-mammalian homolog vasotocin (VT) are secreted from the posterior pituitary to control various physiological phenomena via G protein-coupled receptors. The six known subtypes of VP/VT receptor family (V1a/bR and V2a/b/c/dR) originate from a single ancestral molecule, that most likely coupled with Gα_q and used Ca²⁺ for signaling. However, among the current VP/VT receptors, V2aR predominantly couples with Gα_s and increases intracellular cAMP levels. This receptor is also known to mediate the potent antidiuretic effect of VP/VT, and therefore is clinically important. Although the structure-function relationship of V2R has been of great interest to researchers, an evolutionary perspective was missing; how did the ancestral V2aR switched its G protein selectivity? To address this question, a comparative study between V2aR and its Ca²⁺-signaling cognates (V2b/c/dR) is needed. The aim of the present study was to identify residues/motifs that are crucial to cAMP signaling by V2aR; chimeric receptors were engineered using the functional V2aR and V2bR of medaka. <em>In vitro</em> assays demonstrated that Gα_s-coupling ability of the receptors can be altered by swapping a single residue in the second intracellular loop (ICL2), without affecting Gα_q-coupling ability. The three-dimensional models predicted <em>in silico</em> suggested that the interaction between ICL2 and Gα_s-αN chain and Gα_s-β2/β3 loop contributes to the stabilization of the signaling complex, enhancing the receptor’s capacity to stimulate cAMP pathway upon ligand binding. These findings provide new insights into the molecular and functional evolution of V2aR, as well as into the mechanisms of G protein selectivity of GPCR.</div></div>","PeriodicalId":12582,"journal":{"name":"General and comparative endocrinology","volume":"370 ","pages":"Article 114758"},"PeriodicalIF":2.1,"publicationDate":"2025-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144230937","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":"Cholecystokinin and gastrin-releasing peptide differentially inhibit appetite of rainbow trout","authors":"Antti Forsman ,&nbsp;Elisabeth Jönsson ,&nbsp;Björn Thrandur Björnsson ,&nbsp;Katja Anttila ,&nbsp;Kari Ruohonen","doi":"10.1016/j.ygcen.2025.114757","DOIUrl":"10.1016/j.ygcen.2025.114757","url":null,"abstract":"<div><div>The appetite in fish is a multifaceted phenomenon that comprises specialized interactions between brain and peripheral signals, and as a result, appetite is either stimulated or inhibited. Cholecystokinin (Cck) and gastrin-releasing peptide (Grp) are two postprandially released gastrointestinal peptide hormones that affect feed intake in fish. As the stimulatory or inhibitory effects of hormones can vary in duration and strength, making the nature of hormone effects dynamic, we modelled the dynamics of Cck and Grp using a direct, non-stressful approach. Fish were hormonally treated through an intraperitoneal cannula and feed intake was monitored for 12 h post-injection using a self-feeder system. Cck and Grp decreased feed intake in a dose-dependent manner, hormone-specific both in terms of magnitude and duration. Cck had an immediate inhibitory effect on feed intake, which lasted two–three hours, whereas the immediate inhibitory effect of Grp lasted for the entire 12-hour observation period. The data suggest that Cck acts as a short-term satiety signal in rainbow trout, while Grp acts as a longer-term appetite suppressor.</div></div>","PeriodicalId":12582,"journal":{"name":"General and comparative endocrinology","volume":"370 ","pages":"Article 114757"},"PeriodicalIF":2.1,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144225101","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}