Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology最新文献

{"title":"Time-course of mRNA abundance of appetite-regulatory genes in the brain of rainbow trout fed a plant-based diet from the first feeding","authors":"Cristina Fernández-Maestú ,&nbsp;Maud Martinat ,&nbsp;Jessica Calo ,&nbsp;Cristina Velasco ,&nbsp;José L. Soengas ,&nbsp;Jérôme Roy ,&nbsp;Ayelén M. Blanco","doi":"10.1016/j.cbpa.2025.111939","DOIUrl":"10.1016/j.cbpa.2025.111939","url":null,"abstract":"<div><div>The early developmental stages of fish are critical for improving feeding strategies and growth performance. Understanding feeding-regulatory mechanisms from the earliest stages of development is crucial, especially in the context of aquaculture, where early nutrition has a significant impact on feeding behaviour, growth and survival. This is particularly relevant in carnivorous species, such as rainbow trout (<em>Oncorhynchus mykiss</em>), where the complete replacement of fishmeal and fish oil with plant-based ingredients has negative effects on growth performance and early stage survival. This study investigates the time-course of mRNA abundance of genes encoding key appetite-regulatory neuropeptides and integrative signalling pathways from first feeding to 100 days post-feeding with either a commercial-like diet containing fishmeal and fish oil or a plant-based diet devoid of these marine-derived ingredients. Results showed that an initial diet based on plants does not notably affect the levels of mRNA for appetite-regulating neuropeptides in the brain of rainbow trout alevins. However, the plant-based diet induced slightly distinct patterns in gene mRNA abundance after the first meal, which may underpin reduced feed intake and growth performance. Some key appetite-regulatory neuropeptides, such as neuropeptide Y (<em>npy</em>) and cocaine- and amphetamine-regulated transcript (<em>cartpt</em>), exhibited progressive higher levels in the brain over time, while agouti-related protein 1 (<em>agrp1</em>) and pro-opiomelanocortin a1 (<em>pomca1</em>) levels decreased following initial feeding. Moreover, the expression of key integrative signalling components, including AMP-activated kinase α2 (<em>pkraa2</em>), mechanistic target of rapamycin (<em>mtor</em>), cAMP response-element binding protein 1 (<em>creb1</em>), and forkhead box O1 (<em>foxo1</em>), increased throughout growth, but their abundance was modulated differently by the dietary treatments. This study underscores the importance of understanding neuroendocrine responses to dietary formulations for optimizing aquafeeds and enhancing sustainability in aquaculture.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"310 ","pages":"Article 111939"},"PeriodicalIF":2.2,"publicationDate":"2025-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145253672","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of capture method and handling time on the physiological stress responses of a benthic elasmobranch","authors":"Esha M. Sarai ,&nbsp;Thomas M. Clarke ,&nbsp;Isabel E. Colton ,&nbsp;Apoorva Gopinath ,&nbsp;Chloe N. Roberts ,&nbsp;Charlie Huveneers ,&nbsp;Ondi L. Crino","doi":"10.1016/j.cbpa.2025.111940","DOIUrl":"10.1016/j.cbpa.2025.111940","url":null,"abstract":"<div><div>Marine animals are increasingly exposed to anthropogenic disturbances that disrupt their behaviour and induce physiological stress. In vertebrates, stressors such as anthropogenic disturbances increase the production of glucocorticoid hormones. Although sharks are one of the most threatened groups of marine animals, relatively little is known about their glucocorticoid physiology. We investigated how different capture methods (hand capture and rod and reel) affected physiological stress responses of Port Jackson sharks (<em>Heterondontus portusjacksoni</em>). We measured lactate and glucose levels immediately following capture and over 60-min in the field using point-of-care (POC) devices. We then validated our glucose and lactate measurements using traditional laboratory assays. Additionally, we measured two hormones associated with glucocorticoid physiology (adrenocorticotropic hormone and corticosterone). Point-of-care devices could reliably measure lactate levels of Port Jackson sharks, but not glucose levels. Lactate and corticosterone levels increased over the 60-min holding period post-capture. Sharks captured by hand had higher corticosterone levels but similar lactate levels to sharks caught by rod and reel. While the use of hooks can lead to physical injuries when capturing sharks, our findings challenge the assumption that capturing sharks by hand is less stressful than rod and reel with heavy tackle. Our study highlights the potential use of POC devices to measure metrics associated with physiological stress responses in sharks and increases our understanding of the effects of capture methods and anthropogenic disturbances on shark stress responses.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"310 ","pages":"Article 111940"},"PeriodicalIF":2.2,"publicationDate":"2025-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145240381","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Osteocalcin plasticity and enhanced colocalization with Gprc6A may contribute to musculoskeletal maintenance in hibernating Daurian ground squirrels","authors":"Yue He ,&nbsp;Kai Dang ,&nbsp;Yong Kong ,&nbsp;Fangyang Pan ,&nbsp;Mu Cui ,&nbsp;Yuhong Niu ,&nbsp;Yongai Zhang","doi":"10.1016/j.cbpa.2025.111941","DOIUrl":"10.1016/j.cbpa.2025.111941","url":null,"abstract":"<div><h3>Objectives</h3><div>Hibernating mammals provide a natural model for investigating mechanisms of resistance to disuse-induced musculoskeletal degeneration. However, the molecular pathways enabling muscle and bone preservation during prolonged inactivity remain insufficiently defined. This study examined the temporal dynamics of osteocalcin and its receptor G protein-coupled receptor family C group 6 member A (Gprc6A) across hibernation states in Daurian ground squirrels (<em>Spermophilus dauricus</em>) to elucidate potential mechanisms of musculoskeletal maintenance during torpor-arousal cycles.</div></div><div><h3>Methods</h3><div>Hindlimb muscle and bone mass, along with tibial bone microstructure, were quantitatively assessed at key hibernation phases. Serum osteocalcin concentrations and expression profiles of osteocalcin and Gprc6A were evaluated by western blotting and immunofluorescent colocalization analyses.</div></div><div><h3>Results</h3><div>Musculoskeletal mass and tibial microstructure exhibited only minor changes across hibernation periods (<em>P</em> &gt; 0.05). Tibial osteocalcin expression decreased significantly during torpor compared to the summer active phase but was restored during interbout arousal. In the soleus (SOL) and extensor digitorum longus (EDL) muscles, osteocalcin expression was markedly up-regulated during interbout arousal relative to torpor (<em>P</em> &lt; 0.05). Gprc6A expression in the EDL also increased significantly during interbout arousal compared to summer and torpor phases. Enhanced colocalization of osteocalcin and Gprc6A was observed in both tibial bone and EDL muscle during torpor (<em>P</em> &lt; 0.05).</div></div><div><h3>Conclusion</h3><div>Daurian ground squirrels exhibited remarkable musculoskeletal resilience during prolonged hibernation, maintaining structural integrity despite extended inactivity. Oscillatory expression of osteocalcin and Gprc6A during arousal phases, combined with sustained ligand-receptor colocalization during torpor, may constitute a coordinated endocrine-musculoskeletal adaptation that preserves tissue function during hibernation.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"310 ","pages":"Article 111941"},"PeriodicalIF":2.2,"publicationDate":"2025-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145240388","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of α-dicarbonyl compounds on cell viability in chicken myoblasts","authors":"Meiko Okino ,&nbsp;Ryosuke Makino ,&nbsp;Tetsuya Tachibana","doi":"10.1016/j.cbpa.2025.111937","DOIUrl":"10.1016/j.cbpa.2025.111937","url":null,"abstract":"<div><div>Alpha-dicarbonyl compounds (α-DCs), such as glyoxal (GO) and methylglyoxal (MGO), are highly reactive compounds produced from glucose through various chemical reactions. Diabetic patients with chronic hyperglycemia exhibit higher blood concentrations of GO and MGO than healthy individuals. GO and MGO are cytotoxic to various mammalian cells and are associated with diabetic complications. Given that chickens are hyperglycemic animals, they would possess high levels of GO and MGO in their blood. However, the cytotoxic effects of GO and MGO have not been elucidated in chicken cells. The purpose of the present study was to clarify the effects of GO and MGO on the viability of chicken myoblasts. The two α-DCs decreased the level of intracellular nicotinamide adenine dinucleotide (reduced form), which is an indicator of cell viability, cell proliferation, and energy metabolism. However, neither of the two α-DCs induced apoptotic cell death, production of reactive oxygen species, or lipid peroxidation. In addition, GO and MGO did not induce mitochondrial dysfunction. The present study demonstrated that GO and MGO would have adverse effects on myogenesis in chickens.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"310 ","pages":"Article 111937"},"PeriodicalIF":2.2,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145214523","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seasonality effects on the inflammatory and antioxidant responses in the gilthead seabream (Sparus aurata)","authors":"Vasiliki Makri ,&nbsp;Konstantinos Feidantsis ,&nbsp;Ioannis A. Giantsis ,&nbsp;Ioannis Georgoulis ,&nbsp;Cosmas Nathanailides ,&nbsp;Basile Michaelidis","doi":"10.1016/j.cbpa.2025.111938","DOIUrl":"10.1016/j.cbpa.2025.111938","url":null,"abstract":"<div><div>Mediterranean fish such as <em>Sparus aurata</em> are subjected to extremes of high and low temperature favored by climate change effects, resulting to increased oxidative stress and inflammatory responses. To explore these phenomena, <em>tnf-a</em> and <em>nfkb</em> gene expression, as well as TNF-α and IL-6 levels were evaluated regarding inflammation, while sod, cat and gr gene expression, as well as SOD, GR and catalase activity levels were measured to assess antioxidant response. Findings revealed distinct tissue specific responses, dividing acclimatization phase into distinct cold and warm patterns. In highly vascular tissues (heart and red muscle) increased inflammatory levels were observed at increasing sea water temperatures, highlighting seasonality's strong oxidative effect, which cannot be ameliorated by the increased antioxidant enzymatic response. However, the decreased expression of the antioxidant genes during this period probably highlights energy allocation for processes other than antioxidant defense. An opposite pattern was exhibited in the white muscle and the liver, following the temperature pattern, with lowering levels with decreasing temperatures, probably showing a metabolic depression during decreased temperatures, and an increasing trend (mostly regarding antioxidant defense) during warming. These adjustments enlighten the adaptive responses of fish which reflect fluctuations of seasonal temperature, and the underlying thermal tolerance mechanisms during exposure to seasonal environmental oxidative stress. Understanding these responses helps scientists learn how fish cope with climate-related stress, which is important for managing fish populations and supporting sustainable aquaculture in a warming world.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"310 ","pages":"Article 111938"},"PeriodicalIF":2.2,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145214499","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Growth hormone modulates epithelial intercellular junctions structure and intestinal permeability in zebrafish","authors":"Marcela G. Meirelles ,&nbsp;Camila I.M. Fénero ,&nbsp;Bruna F. Nornberg ,&nbsp;Tony L.R. da Silveira ,&nbsp;Mateus T. Kütter ,&nbsp;Niels Olsen S. Camara ,&nbsp;Luis Fernando Marins","doi":"10.1016/j.cbpa.2025.111936","DOIUrl":"10.1016/j.cbpa.2025.111936","url":null,"abstract":"<div><div>Intestinal permeability refers to the regulated passage of luminal contents into the internal milieu via transcellular or paracellular routes. Tight junctions (TJs), components of the apical junctional complex (AJC), are critical determinants of paracellular permeability and intestinal barrier integrity. Disruptions in growth hormone (GH) signaling have been implicated in gastrointestinal dysfunction; however, the effects of chronically elevated GH levels on intestinal barrier function remain poorly understood. In this study, we investigated whether GH overexpression affects intestinal permeability and epithelial structure using a transgenic zebrafish model. <em>gh</em>-transgenic zebrafish and their non-transgenic full siblings were evaluated for intestinal architecture and barrier function. Images of transmission electron microscopy revealed a greater frequency of AJC disruption in <em>gh</em>-transgenic fish. These ultrastructural changes were associated with increased transcription of TJ-related genes, including <em>cldn15a</em>, <em>oclna</em>, and <em>zo1a</em>, as assessed by qRT-PCR, and a higher intestinal permeability to macromolecule (RITC-dextran 10,000 MW). These findings demonstrate that chronic <em>gh</em> overexpression alters intercellular epithelial architecture and enhances intestinal paracellular permeability. This may reflect an adaptive mechanism to meet increased energy demands under anabolic conditions. Moreover, these results suggest a mechanistic link between GH signaling pathways and modulation of the intestinal barrier, with potential implications for biomedical science.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"310 ","pages":"Article 111936"},"PeriodicalIF":2.2,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145214561","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microplastics affect food intake and the expression of appetite regulators and nutrient transporters in pond loach (Misgurnus anguillicaudatus)","authors":"Thanushanthahi Loganathan,&nbsp;Julianna Dyke,&nbsp;Helene Volkoff","doi":"10.1016/j.cbpa.2025.111935","DOIUrl":"10.1016/j.cbpa.2025.111935","url":null,"abstract":"<div><div>Microplastics (MPs) are emerging pollutants in freshwater ecosystems, posing risks to aquatic organisms. This study examines the effects of dietary MP exposure on food intake, appetite regulation, and nutrient transporter expression in pond loach (<em>Misgurnus anguillicaudatus</em>), a sediment-feeding facultative air breathing freshwater fish. Fish were exposed to small (250–300 μm), medium (425–500 μm), and large (710–850 μm) polyethylene microspheres for two weeks. Food intake was significantly reduced in fish fed small and medium MPs, but not large MPs, suggesting size-dependent ingestion effects. In the brain, MP (425–500 μm) exposure suppressed <em>orexin</em> expression, a key appetite-stimulating neuropeptide, while other central appetite regulators remained unchanged. In the anterior intestine, anorexigenic peptides such as cholecystokinin (<em>cck</em>) and peptide YY (<em>pyy</em>) were upregulated, alongside glucose-dependent insulinotropic polypeptide (<em>gip</em>), indicating enhanced satiety signaling. Sodium-dependent glucose transporter 1 (<em>slc5a1</em>) expression was downregulated, suggesting impaired glucose absorption. MPs induced upregulation of <em>gip</em> and urea transporter 2 (<em>slc14a2</em>) in the mid intestine, and <em>pyy</em>, <em>gip</em>, glucose transporter 1 (<em>slc2a1</em>), urea transporter 2 and hypoxia-inducible factor 1α (<em>hif1a</em>) in the posterior intestine. These results show that MP exposure disrupts feeding, alters endocrine signaling, and affects nutrient absorption in pond loach, highlighting the physiological sensitivity of sediment-feeding fish to MP contamination and the ecological risks posed by plastic pollution to aquatic species and ecosystems.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"310 ","pages":"Article 111935"},"PeriodicalIF":2.2,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145182347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reproductive gene expression in female broodstock European flat oyster, Ostrea edulis, under ambient and constant temperature and photoperiod regimes","authors":"Mairi E. Cowan ,&nbsp;Eduardo Jimenez-Fernandez ,&nbsp;Aaliyah Malla ,&nbsp;Adam D. Hughes","doi":"10.1016/j.cbpa.2025.111934","DOIUrl":"10.1016/j.cbpa.2025.111934","url":null,"abstract":"<div><div>The European flat oyster (<em>Ostrea edulis</em>) is a species of significant ecological, commercial and cultural importance. Interest in scaling up its production is growing rapidly, however, challenges in managing reproduction in culture remain. This study aimed to improve understanding of reproductive control in female broodstock by analysing the gene expression of the key endocrine factors APGWamide, GnRH (gonadotropin releasing hormone) and GPB5 in the visceral ganglion, as well as vitellogenin in the gonads. This was performed alongside histological classification of individuals by sex and reproductive stage. Oysters were subjected to three different conditioning regimes: a reference regime consisting of ambient temperature and a long-day photoperiod of 18-h light: 6-h dark (REF(Amb/18:6)), and separately, two constant temperature regimes of 14 °C, either under simulated natural photoperiod (14C/NP) or constant 24-h light (14C/LL). Histology revealed a female-to-male shift across regimes. Gametogenesis progressed under all conditions, but females under constant light (14C/LL) showed less uniform development. <em>Apgwamide</em> expression significantly increased as females developed across all regimes. <em>Vitellogenin</em> expression also significantly increased over time and with gametogenesis under the REF(Amb/18:6) and 14C/NP regimes. No clear patterns were observed for <em>gnrh</em> and <em>gpb5</em> expression in this dataset, though their roles in reproduction cannot be excluded. Altogether, these findings support APGWamide and vitellogenin as key factors of interest in female reproduction, with light, as well as the known effects of temperature, influencing development. This research provides insights to support broodstock conditioning and European flat oyster production and restoration efforts.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"310 ","pages":"Article 111934"},"PeriodicalIF":2.2,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145182388","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Temperature drives the pace, not the price, of postprandial growth in Burmese pythons (Python bivittatus)","authors":"Katja B. Last,&nbsp;Terese Bech Eriksen,&nbsp;Emil Rindom,&nbsp;Tobias Wang","doi":"10.1016/j.cbpa.2025.111933","DOIUrl":"10.1016/j.cbpa.2025.111933","url":null,"abstract":"<div><div>Body temperature influences all physiological processes in ectotherms, including the rise in metabolism upon feeding (SDA response). In reptiles, elevated temperatures increase the magnitude of the SDA response but shorten its duration with total energy expenditure remaining unaffected. Recent studies show that feeding induces a several-fold elevation of protein synthesis in various organs of pythons, but the effects of temperature on postprandial protein synthesis remain unexplored. We therefore measured relative changes in postprandial protein synthesis in skeletal muscle and visceral organs of the Burmese pythons (<em>Python bivittatus</em>) as well as the rate of oxygen consumption (V̇O₂) and mass of selected organs at 25 and 35 °C. Measurement were made at the peak of the SDA response (72 and 24 h post feeding at 25 and 35 °C, respectively). Protein synthesis was assessed from the rate of puromycin-incorporation and V̇O₂ was measured with closed respirometry. As expected, V̇O₂ increased with temperature in both fasted and digesting snakes. Feeding induced a several fold rise in protein synthesis, with higher rates at 35 compared to 25 °C in most tissues, but mass specific organ masses were similar between fed snakes at both temperatures. This supports the concept that SDA represents the energetic cost of growth, resulting in the same level of growth is achieved over a shorter period for the 35 °C group compared to the 25 °C group. Moreover, the strong correlation between organ-specific protein synthesis and V̇O₂ further reinforces this concept. Our results demonstrate that elevated temperature accelerates postprandial protein synthesis without changing total growth, suggesting that temperature effects on the SDA response are primarily mediated by changes in the rate of protein synthesis.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"310 ","pages":"Article 111933"},"PeriodicalIF":2.2,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145151622","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Response of rainbow trout mucosal tissues under repeated hypoxia episodes","authors":"Irene García-Meilán ,&nbsp;Nuria Ruiz ,&nbsp;Lluís Tort","doi":"10.1016/j.cbpa.2025.111931","DOIUrl":"10.1016/j.cbpa.2025.111931","url":null,"abstract":"<div><div><strong>Hypoxic events are common in both natural and aquaculture environments due to external factors or anthropogenic activities. To cope with this fluctuating environment, fish activate complex systemic stress responses, but less is known about their mucosal responses. To investigate this, five experimental groups were established: absolute control (AC), manipulated control (MC), and three groups exposed to a single hypoxic shock (H1) or repeated hypoxic shocks (H2 and H3), sampled at 1, 6, and 24</strong> <strong>h after hypoxia. Mucus cortisol levels increased 1</strong> <strong>h after manipulation and hypoxic shocks, confirming that the stress response was activated. However, cortisol levels decreased as the fish underwent more shocks. A significant up-regulation of the <em>crh</em> gene by treatment was observed in the gills, while no expression was detected in the intestine. Additionally, an up-regulation of <em>gr1</em> and <em>mr</em> gene expression was found in the gills, whereas the skin and intestine showed an opposite response, with gene expression returning to control levels after the third hypoxic shock (H3).</strong> <em><strong>Hif-1</strong>α</em> <strong>and <em>myoglobin</em> gene expression showed clear tissue-specific regulation, likely related to their primary functions. In the skin and intestine, as <em>hif-1α</em> levels increased, <em>myoglobin</em> expression decreased, while in the gills, the opposite pattern was observed, with higher <em>myoglobin</em> expression during the reoxygenation phase. Overall, the results suggest that repeated hypoxia promotes tolerance and a certain degree of habituation in rainbow trout, without compromising their survival.</strong></div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"310 ","pages":"Article 111931"},"PeriodicalIF":2.2,"publicationDate":"2025-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145115098","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}