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

{"title":"Acclimation to moderate hypoxia improves acute hypoxia tolerance of diploid and triploid brook charr, Salvelinus fontinalis","authors":"Sarah A. McGeachy,&nbsp;Tillmann J. Benfey","doi":"10.1016/j.cbpa.2025.111957","DOIUrl":"10.1016/j.cbpa.2025.111957","url":null,"abstract":"<div><div>Triploid salmonids are used in aquaculture and stocking programs for recreational fishing because they are reproductively sterile and therefore cannot breed in the wild. However, they appear to be more sensitive than diploids to environmental stressors. The objective of this study was to develop a better understanding of the hypoxia tolerance of triploids. We compared the acute hypoxia tolerance of sibling diploid and triploid brook charr that were acclimated to either moderate hypoxia (65 % of air saturation) or normoxia (98 % air saturation). Fish then underwent acute hypoxia trials, by slowly injecting nitrogen gas to displace oxygen and using loss of equilibrium (LOE) as the endpoint. The fish acclimated to moderate hypoxia had a lower oxygen tension (PO₂) at LOE compared to fish acclimated to normoxia, regardless of ploidy. Ploidy did not affect time to LOE, but triploids had a higher PO₂ at LOE (i.e., were less tolerant of acute hypoxia) compared to diploids. Potential predictors of acute hypoxia tolerance (hematocrit, blood glucose, blood lactate, relative ventricular mass, hepatosomatic index, condition factor, compact myocardium thickness, and interlamellar cell mass) did not provide conclusive results. However, relative interlamellar cell mass size was larger in triploids, suggesting reduced functional gill surface area for respiratory gas exchange as a possible explanation for their reduced acute hypoxia tolerance. This study has shown the capacity for moderate hypoxia acclimation to improve triploid performance, although not to the same extent as for diploids.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"311 ","pages":"Article 111957"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145623949","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":"Evaluating bioelectrical impedance analysis (BIA) as a tool for assessing freshwater fish condition","authors":"Maxwell C. Mallett ,&nbsp;Jason D. Thiem ,&nbsp;Gavin L. Butler ,&nbsp;Luke Carpenter-Bundhoo ,&nbsp;Curtis Champion ,&nbsp;Mark J. Kennard","doi":"10.1016/j.cbpa.2025.111958","DOIUrl":"10.1016/j.cbpa.2025.111958","url":null,"abstract":"<div><div>The nutritional status, or condition, of fish is a key health proxy influencing vital life history processes including migration, reproduction, and recruitment. Numerous morphological, biochemical, and electronic metrics are used to assess fish condition, yet it remains unclear if these metrics are congruent with each other and across species. This study evaluates bioelectrical impedance analysis (BIA) as a tool for assessing fish condition by comparing it with morphological (e.g. condition index, hepatosomatic index) and biochemical (e.g. percentage and total-body mass compositions of lipid, mineral, protein and water content and bulk C:N ratios in muscle tissue) condition metrics in three native Australian fish species (<em>Macquaria ambigua</em>, <em>Nematalosa erebi</em>, and <em>Percalates novemaculeata</em>) and one invasive species (<em>Cyprinus carpio)</em>. Using simple least-squares linear regressions and Principal Component Analysis (PCA), we uncovered that BIA parameters correlated strongly with total-body masses of biochemical components that covary with body size, but showed weaker correlations with percentage compositions of the same components. However, phase angle, a common BIA measure, showed some significant correlations with morphological condition and lipid content, although these relationships were generally weak and species dependent. These findings suggest that BIA can effectively estimate certain physiological parameters, but caution should be applied when interpreting BIA metrics, as their relationship with established indicators of condition may vary. The current study underscores the importance of combining multiple methods to provide a comprehensive understanding of fish condition in freshwater ecosystems, which can be used to provide mechanistic linkages with anthropogenic impacts.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"311 ","pages":"Article 111958"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145623950","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":"Vitellogenin and its receptor characterize exogenous vitellogenesis mode in the Pacific white shrimp Litopenaeus vannamei","authors":"Ying Lu ,&nbsp;Shuai Zhou ,&nbsp;Jiawang Cao ,&nbsp;Juan Sui ,&nbsp;Xue Chen ,&nbsp;Kai Liu ,&nbsp;Zhaoxin Wang ,&nbsp;Zhifeng Zhang ,&nbsp;Zhenkui Qin ,&nbsp;Jie Kong","doi":"10.1016/j.cbpa.2025.111947","DOIUrl":"10.1016/j.cbpa.2025.111947","url":null,"abstract":"<div><div>Vitellogenesis is a pivotal process of animal reproduction, characterized by yolk protein formation and accumulation in developing oocytes. Vitellogenin (Vg), the precursor of vitellin (Vn), serves as the primary yolk component. While animals employ both exogenous and endogenous vitellogenesis, the precise synthetic locus of Vg in the Pacific white shrimp <em>Litopenaeus vannamei</em>, the globally most important cultured shrimp, remains unclear. To characterize vitellogenesis and its regulatory mode, the present study examined ovarian morphology, gonadosomatic index (GSI) dynamics, hepatopancreatic and ovarian histology, as well as spatiotemporal expression and cellular localization of Vg and its receptor vitellogenin receptor (VgR), during gonadal development process<em>.</em> We discovered that <em>L. vannamei</em> ovarian cycle was categorized into five stages, marked by ovarian color transition from khaki to dark green and progressive GSI increase. <em>In situ</em> hybridization revealed <em>Vg</em> mRNA in hepatopancreatic Blasenzellen and Restzellen cells and ovarian follicular cells, but not in oocytes. Immunofluorescence showed Vg protein primarily in hepatopancreatic cells and oocytes, while VgR localized to the membrane of vitellogenic oocytes, forming complexes with exogenous Vg cytoplasmic internalization. Collectively, this study established a standardized ovarian staging system for <em>L. vannamei</em>, demonstrated an exogenous vitellogenesis mode, with hepatopancreas and ovarian follicle cells as the primary Vg synthesis sites, and elucidated the cooperative role of Vg and VgR in yolk protein uptake and deposition<em>.</em> These findings advance our understanding of crustacean reproductive biology and provide a theoretical foundation for optimizing shrimp fecundity and aquaculture practices.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"311 ","pages":"Article 111947"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145460764","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 heat stress on HSP70 and Na+/K+-ATPase expressions in the gills of juvenile goldfish: Focus on tissue architecture, mucus secretion and protein nitration","authors":"Ngozichukwu Francis Ngozichukwu ,&nbsp;Md Saydur Rahman","doi":"10.1016/j.cbpa.2025.111959","DOIUrl":"10.1016/j.cbpa.2025.111959","url":null,"abstract":"<div><div>Global warming has worsened heat stress on aquatic habitats, creating physiological challenges for ectothermic animals such as teleost fish. The fish gill, a multifunctional organ responsible for gas exchange and osmoregulation, is especially vulnerable to environmental stress. This study examined how elevated temperatures affect the gills of juvenile goldfish (<em>Carassius auratus</em>) under simulated climate conditions. Fish were exposed to control (22 °C), medium (28 °C), and high (32 °C) temperature settings for two weeks. Histological evaluations showed significant structural changes, including lamellar fusion, epithelial detachment, and edema in the high-temperature groups, indicating tissue injury and decreased function. Immunohistochemical and real-time qRT-PCR analyses revealed notable alterations in key stress biomarkers following heat exposure. Heat shock protein 70 (HSP70, a chaperone protein) expression and mRNA levels increased significantly (<em>P</em>&lt;0.05) during heat stress, suggesting activation of cellular defense against protein denaturation. Additionally, higher expression of 3-nitrotyrosine protein, a marker of protein nitration, indicated nitrative stress likely caused by excess reactive nitrogen species during heat stress. The expression and mRNA levels of Na⁺/K⁺-ATPase, an enzyme in ion regulation, were significantly reduced (<em>P</em>&lt;0.05) in the gills of heat-stressed fish, indicating compromised osmoregulatory ability. These findings suggest that fish gills show unique morphological and molecular responses to elevated temperature, highlighting their sensitivity as early indicators of heat stress. They also show how nitrative stress arises from high temperatures and underscore the broader ecological impacts of climate change on teleost species. Understanding these biological and molecular responses are essential for developing models to predict the effects of global climate change.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"311 ","pages":"Article 111959"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145745822","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":"Microplastic impacts physiological mechanisms of marine, diadromous, and freshwater crustaceans","authors":"Héllen Siqueira Leite ,&nbsp;Juliana Rodrigues da Costa ,&nbsp;Barbara Bernardes Calbo ,&nbsp;Mariana Capparelli ,&nbsp;Claudia Neves ,&nbsp;Giovanna Teixeira Gimiliani ,&nbsp;Alessandra Augusto","doi":"10.1016/j.cbpa.2025.111946","DOIUrl":"10.1016/j.cbpa.2025.111946","url":null,"abstract":"<div><div>The effects of microplastic on species inhabiting different saline gradients remain unclear, particularly the impact of glitter particles. We investigated the effects of glitter on the physiological mechanisms of species from various saline environments using the following models: a marine/estuarine shrimp (<em>Penaeus vannamei</em>), a diadromous shrimp (<em>Macrobrachium amazonicum</em>), and an exclusively freshwater shrimp (<em>Macrobrachium potiuna</em>). The animals were exposed to varying glitter concentrations (0, 0.4, 4 and 40 mg.L⁻¹) for 10 days, and to the salinities where they are found in nature. In addition, we evaluated the ability of one of the species (<em>P. vannamei</em>) to recover its physiology and morphology when transferred to glitter-free water after previous exposure to the pollutant for six days. We examined multiple mechanisms, including oxygen consumption, nitrogen excretion, hepatosomatic index, energy substrate oxidation, and osmoregulation. <em>P. vannamei</em> showed 13 % mortality at salinity 30. Physiological parameters exhibited specific variations in response to salinity and/or glitter concentration. Glitter exposure affected oxygen consumption in all three species, but with contrasting responses: <em>P. vannamei</em> exhibited increases up to ∼200 % (depending on salinity), likely due to elevated energy demands, while <em>M. amazonicum</em> and <em>M. potiuna</em> showed reductions up to 70 %, potentially indicating gill damage. In <em>M. amazonicum</em>, glitter exposure enhanced the species' hyperosmotic regulatory capacity. <em>Penaeus vannamei</em> could not recover its hepatosomatic index and gill and intestinal morphologies after being transferred to glitter-free water. We conclude that glitter significantly alters physiological functions related to energy metabolism and osmoregulation. However, since these responses are salinity-dependent, the ability to migrate across different salinity gradients may provide an adaptive advantage for species exhibiting such behavior. The results obtained provide significant insights into the response of shrimps from different saline gradients to microplastics, which is still a major gap in our knowledge.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"311 ","pages":"Article 111946"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145440044","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":"2025-12-01","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}

{"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":"2025-12-01","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":"Born in complexity: How the early life environment shapes zebrafish larvae phenotype","authors":"Julia A. Bourdeau,&nbsp;Sarah L. Alderman","doi":"10.1016/j.cbpa.2025.111930","DOIUrl":"10.1016/j.cbpa.2025.111930","url":null,"abstract":"<div><div>The biotic and abiotic environments are potent drivers of individual plasticity. Zebrafish, a popular research model around the world, has been extensively used for understanding the proximate cause and mechanisms of phenotypic plasticity to environmental enrichment. Despite awareness of providing high-standard rearing condition for increasing fish welfare, rearing of zebrafish larvae involves little more than stable temperature and daily water changes. We asked whether including Lego bricks as additional visual and mechanosensory stimuli during early rearing would induce developmental plasticity across morphological (growth, forebrain cell proliferation), physiological (stress response), and behavioural (anxiety, habituation) endpoints. We raised zebrafish in Petri dishes with complexity (Lego bricks) from fertilization to 5 days post-fertilization (dpf) and then compared phenotypes to those of traditionally reared larvae (barren). Relative to barren-reared larvae, those raised with complexity were shorter and did not increase whole body cortisol in response to an acute agitation stressor. Forebrain cell proliferation was not different between treatments, however, larvae raised with complexity habituated sooner to an adverse stimulus and showed a tendency towards reduced anxiety-like behaviour, suggesting the anxiolytic effects of environmental enrichment may be initiated at early life stages. Taken together, our results invite consideration into how current practices in raising zebrafish may influence neurodevelopment and behavioural research findings, and may be applied to improve outcomes in fish breeding programs for conservation initiatives.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"310 ","pages":"Article 111930"},"PeriodicalIF":2.2,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145088457","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":"2025-12-01","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":"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":"2025-12-01","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}