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

{"title":"Evaluation of stress in farmed Atlantic salmon (Salmo salar) using different biological matrices","authors":"Rouzbeh Keihani ,&nbsp;Ana S. Gomes ,&nbsp;Pablo Balseiro ,&nbsp;Sigurd O. Handeland ,&nbsp;Marnix Gorissen ,&nbsp;Augustine Arukwe","doi":"10.1016/j.cbpa.2024.111743","DOIUrl":"10.1016/j.cbpa.2024.111743","url":null,"abstract":"<div><p>Atlantic salmon were subjected to an acute crowding scenario, and their subsequent stress responses were observed under three distinct swimming speed/water flow (WF) conditions: 0.5, 1, and 1.5 body lengths per second (BL/s). Feces, dermal mucus, and plasma were collected for analysis at 1, 6, and 24 h (h) post-stress. Additionally, the head kidney and two regions of the brain (pituitary and POA) were collected for transcript expression analysis. Fish swimming at 0.5 BL/s exhibited higher pre-stress (baseline) cortisol levels. Across all groups and matrices, the highest cortisol/cortisol metabolites (CM) levels were observed at the 1 h post-stress sampling point. At 6 h (second sampling time point), a clear decline toward baseline levels were observe in all groups. Significant increases in mean plasma glucose levels were observed at 1 h post-stress for all groups. The mean plasma lactate levels varied based on WF treatments, with a significant increase observed at 1 h only for the 1.5 BL/s group. Additionally, significant decreases in mean plasma lactate were noted at 6 and 24 h post-stress for some groups. The mRNA abundances of the tested genes (<em>star, cyp17a1, hsd11β2, srd5a1</em>) increased following the stress events. These changes were not uniform across all groups and were tissue dependent. In summary, the results indicate that mucus and feces can be used as potentially less invasive matrices than blood for evaluating stress and, consequently, the welfare of Atlantic salmon in captivity.</p></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"298 ","pages":"Article 111743"},"PeriodicalIF":2.1,"publicationDate":"2024-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1095643324001703/pdfft?md5=d9308092722e1d03a55d39b9112e6f37&pid=1-s2.0-S1095643324001703-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142241986","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of dietary indispensable amino acid deficiencies on feed intake in stomachless fish","authors":"Giovanni S. Molinari ,&nbsp;Michal Wojno ,&nbsp;Karolina Kwasek","doi":"10.1016/j.cbpa.2024.111742","DOIUrl":"10.1016/j.cbpa.2024.111742","url":null,"abstract":"<div><p>Evidence suggests that fish are more tolerant than mammals to imbalanced dietary amino acid profiles. However, the behavioral and physiological responses of fish to individual deficiencies in dietary indispensable amino acids (IDAA) remain unclear. This study examined how stomachless fish respond to diets deficient in limiting IDAA (lysine, methionine, and threonine), using Zebrafish (<em>Danio rerio</em>) as a model. The response to deficient diets was assessed based on; 1) growth performance and feeding efficiency; 2) feed intake; 3) expression of appetite-regulating hormones and nutrient-sensing receptors; and 4) muscle postprandial free amino acid (FAA) levels. There were 6 treatments, each with 3 replicate tanks. A semi-purified diet was formulated for each group. The CG diet was based on casein and gelatin, while the FAA50 diet had 50 % of dietary protein supplied with crystalline amino acids. Both were formulated to contain matching, balanced amino acid profiles. The remaining diets were formulated the same as the FAA50 diet, with minor adjustments to create deficiencies in selected IDAA. The (−) Lys, (−) Met, and (−) Thr diets had lysine, methionine, and threonine withheld from the FAA mix, respectively, and the Def diet was deficient in all three. The juvenile Zebrafish were fed to satiation 3 times daily from 21 to 50 days-post-hatch. Results showed that 50 % replacement of dietary protein with crystalline amino acids significantly reduced growth of juvenile Zebrafish. There were no significant differences in growth between the FAA50 group and groups that received deficient diets. The deficiency of singular IDAA did not induce significant changes in feed intake; however, the combined deficiency in the Def diet caused a significant increase in feed intake. This increased feed intake led to decreased feeding efficiency. A significant decrease in feeding efficiency was also observed in the (−) Lys group. There was an observed upregulation of <em>neuropeptide Y</em> (<em>NPY</em>), an orexigenic hormone, in the Def group. Overall, results from this study suggest stomachless fish increase feed intake when challenged with IDAA-deficient diets, and the regulation of NPY might play a role in this response.</p></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"298 ","pages":"Article 111742"},"PeriodicalIF":2.1,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1095643324001697/pdfft?md5=398c20f7aaab6d28d7599adb88502e51&pid=1-s2.0-S1095643324001697-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142241984","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Paracellular barriers: Advances in assessing their contribution to renal epithelial function","authors":"Sima Jonusaite,&nbsp;Nina Himmerkus","doi":"10.1016/j.cbpa.2024.111741","DOIUrl":"10.1016/j.cbpa.2024.111741","url":null,"abstract":"<div><p>Regulation of salt and water balance occupies a dominant role in the physiology of many animals and often relies on the function of the renal system. In the mammalian kidney, epithelial ion and water transport requires high degree of coordination between the transcellular and paracellular pathways, the latter being defined by the intercellular tight junctions (TJs). TJs seal the paracellular pathway in a highly specialized manner, either by forming a barrier against the passage of solutes and/or water or by allowing the passage of ions and/or water through them. This functional TJ plasticity is now known to be provided by the members of the claudin family of tetraspan proteins. Unlike mammalian nephron, the renal structures of insects, the Malpighian tubules, lack TJs and instead have smooth septate junctions (sSJs) as paracellular barrier forming junctions. Many questions regarding the molecular and functional properties of sSJs remain open but research on model species have begun to inform our understanding. The goal of this commentary is to highlight key concepts and most recent findings that have emerged from the molecular and functional dissection of paracellular barriers in the mammalian and insect renal epithelia.</p></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"298 ","pages":"Article 111741"},"PeriodicalIF":2.1,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1095643324001685/pdfft?md5=09452f0331b901b8cad6985f57320d90&pid=1-s2.0-S1095643324001685-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142241988","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of creatine administration on locomotor activity and stress response in olive flounder (Paralichthys olivaceus)","authors":"Huafeng Zou ,&nbsp;Lehe Lin ,&nbsp;Liangfang Liu ,&nbsp;Mengmeng Shi ,&nbsp;Weiqun Lu","doi":"10.1016/j.cbpa.2024.111740","DOIUrl":"10.1016/j.cbpa.2024.111740","url":null,"abstract":"<div><p>The creatine kinase system is crucial for maintaining cellular energy homeostasis and plays a role in regulating locomotor behavior in organisms, but its significance in the regulating the motionless behavior in olive flounder is limited. In the first experiment of this study, elevated levels of creatine kinase (CK) activity in the spinal cord were detected in the juvenile group (JG) flounder compared to the adult group (AG) flounder. In the second experiment, to further confirm the involvement of CK in the locomotor behavior, the adult flounder was given an intraperitoneal injection of creatine (150 mg/kg), while the flounder in the control group received a saline solution. After one week post-injection, the behavioral analysis revealed that the flounder in the creatine-treated group displayed higher levels of locomotor activity and a greater number of escape attempts in response to external stimuli when compared to the control group. However, the acute stress response, induced by intraperitoneal injection and characterized by tail beating, was significantly alleviated in the flounder in the creatine-treated group. Additionally, there was an upregulation of the <em>UII</em> and <em>AchR</em> genes in the spinal cord, as well as increased levels of <em>UII</em> and <em>AchR</em> in the muscle tissues of the creatine-treated flounder. However, a reduction in <em>UI</em> mRNA levels was observed in the brain of the flounder. Collectively, our data provide the evidence that the elevated enzyme activity and gene expression of creatine kinase play important roles in off-bottom swimming behavior in the JG flounder. Furthermore, administration of creatine improved the locomotor activity and alleviated the stress response in flounder, which is associated with regulation of the locomotor- and stress-related gene in the brain, spinal cord, and muscle.</p></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"298 ","pages":"Article 111740"},"PeriodicalIF":2.1,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142241985","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":"Cloning of down-regulated genes under cold stress and identification of important genes related to cold tolerance in zebrafish (Danio rerio)","authors":"Lang Zhang ,&nbsp;Ziwei Song ,&nbsp;Shan Zhong ,&nbsp;Zongbin Cui","doi":"10.1016/j.cbpa.2024.111739","DOIUrl":"10.1016/j.cbpa.2024.111739","url":null,"abstract":"<div><p>Low-temperature stress poses a significant risk to the survival of both cultivated and wild fish populations. Existing studies have found that the pre-acclimation of fishes to moderate cold stress can stimulate the activation of acclimation pathways, thereby enhancing their tolerance to cold stress. The fitness of fish relies heavily on appropriately controlled transcriptional reactions to environmental changes. Despite previous characterization of gene expression profiles in various fish species during cold acclimation, the specific genes responsible for essential functions in this process remain largely unknown, particularly the down-regulated genes induced by cold acclimation. To investigate the genes involved in cold acclimation, this study employed real-time quantitative PCR (RT-qPCR), molecular cloning, microinjection techniques, and cold stress experiments to determine the genes that play an essential part in cold acclimation. Consequently, 18 genes were discovered to be down-regulated in larval zebrafish experiencing cold stress. All 18 genes successfully detected overexpression in zebrafish at 96 and 126 hpf (fold change ≥3), which declined with the growth of zebrafish. Following microinjection, it was observed that <em>her8a</em>, <em>cyp51</em>, <em>lss</em>, <em>txnipb</em>, and <em>bhlha9</em> had an adverse impact on the survival rate of zebrafish larvae under cold stress. These genes have been identified to play significant roles in various biological processes. For instance, <em>bhlha9</em> has been found to be involved in both limb development and temperature sensing and <em>her8a</em> has been implicated in neural development. Additionally, <em>cyp51</em> and <em>lss</em> have been identified as participants in the cholesterol synthesis pathway. <em>Txnipb</em> has been reported to induce cell apoptosis, thereby potentially influencing the survival rate of zebrafish larvae under cold stress. These findings offered crucial data for the analysis of molecular processes related to cold tolerance and the development of cold-resistant fish breeding.</p></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"298 ","pages":"Article 111739"},"PeriodicalIF":2.1,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142183964","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":"METHODS: Validating an immunoassay to measure fecal glucocorticoid metabolites in yellow-bellied marmots","authors":"Xochitl Ortiz-Ross ,&nbsp;Hash Brown Taha ,&nbsp;Emily Press ,&nbsp;Sarah Rhone ,&nbsp;Daniel T. Blumstein","doi":"10.1016/j.cbpa.2024.111738","DOIUrl":"10.1016/j.cbpa.2024.111738","url":null,"abstract":"<div><p>Quantifying physiological stress in wild animals is essential for understanding their health, reproductive success, and survival in a variable environment. The yellow-bellied marmot (<em>Marmota flaviventer</em>) study at the Rocky Mountain Biological Laboratory near Crested Butte, Colorado, USA is the world's second longest study of free-living mammals. Historically, we used a validated corticosterone radioimmunoassay (RIA) to measure fecal glucocorticoid metabolites (FGMs) as a proxy for physiological stress. However, the costs and risks associated with working with radioisotopes drove us to consider a more sustainable method. Here we evaluate the suitability of two competitive corticosterone enzyme assays (EIA), one from Cayman Chemical Company (CCC) and one from Arbor Assays (AA), to measure marmot FGMs via their cross-reaction. The findings revealed that the AA EIA better matched the RIA in terms of accuracy across high and low FGM concentrations, had superior assay parameters, showed the highest correlations with RIA results and effectively captured the annual variations in FGM concentrations, thus demonstrating its reliability for use in longitudinal studies. We further analytically validated the AA EIA for FGMs and confirmed its efficacy and lack of matrix effects, thus establishing its suitability for ongoing and future studies of FGMs in marmots. The transition to the AA EIA from the RIA ensures continued data integrity while enhancing safety and environmental sustainability.</p></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"298 ","pages":"Article 111738"},"PeriodicalIF":2.1,"publicationDate":"2024-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S109564332400165X/pdfft?md5=e4595b8bc48b5f5007a203a0ffb3aea8&pid=1-s2.0-S109564332400165X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142241987","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Correcting systematic error in PO2 measurement to improve measures of oxygen supply capacity (α)","authors":"Alexander W. Timpe,&nbsp;Brad A. Seibel","doi":"10.1016/j.cbpa.2024.111737","DOIUrl":"10.1016/j.cbpa.2024.111737","url":null,"abstract":"<div><p>An organism's oxygen supply capacity, measured as a ratio of a metabolic rate to its critical oxygen partial pressure, describes the efficacy of oxygen uptake and transport. This metric is sensitive to errors in oxygen measurement, especially near anoxia where the magnitude of instrument error as a proportion of total signal is magnified. Here, we present a conceptual and mathematical method that uses this sensitivity to identify, quantify, and therefore correct oxygen measurements collected using inaccurately calibrated sensors. When appropriate, adding a small correction value to each oxygen measurement counteracts the effects of this error and provides results that are comparable to data from accurately calibrated oxygen probes. We demonstrate, using simulated, laboratory, and literature datasets, how this method can be used post hoc to diagnose error in, correct the magnitude of, and reduce the variability in repeat measures of traits relevant to oxygen tolerance.</p></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"298 ","pages":"Article 111737"},"PeriodicalIF":2.1,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142146928","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":"The ontogeny of white leghorn chicken (Gallus domesticus) blood chemistry changes in response to acute exposure to 10 % O2","authors":"Dane A. Crossley II,&nbsp;James W. Hicks","doi":"10.1016/j.cbpa.2024.111736","DOIUrl":"10.1016/j.cbpa.2024.111736","url":null,"abstract":"<div><p>The embryonic chicken is a valuable model for studying the maturation of cardiovascular physiology and the responses of this organ system to environmental manipulations such as acute hypoxia. Hypoxia determines not only the general cardiovascular response but also is a tool to determine the system's maturation of reflexive control. Several studies suggest embryonic chicken's regulation of the cardiovascular response to hypoxia, but no studies have measured the blood chemistry changes that accompany these responses. To clarify the changes in blood parameters accompanying cardiovascular function changes during acute hypoxia, we designed a study to investigate the blood chemistry (pO₂, pCO₂, pH, lactate, glucose, and blood ions) in developing embryos during acute hypoxia (O₂ = 10 %). Embryos ranging from day 13 to 21 of incubation were sampled during a control period and at the end of a 5-min of hypoxia. Hypoxia caused bradycardia on all days of incubation. The maximal blood hypoxic response occurred on day 15, with lactate increasing 7-fold (2.5 to 16.6 mmol/l) while glucose levels decreased by 50 % (136 to 63 mg/dl). Furthermore, hypoxia reduced pH (7.40 to 7.26), which peaked on day 15. These data indicate that a 5-min exposure to 10 % O₂ is sufficient to induce dramatic changes in blood chemistry however chorioallantoic arterial blood pO₂ was unchanged on most days of the study. Therefore, given the cardiovascular response to hypoxia and the increase in blood lactate prior to airbreathing in the chicken embryo, the embryonic tissues experienced an acute stress that may be the basis for the change in cardiovascular function during the exposure.</p></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"298 ","pages":"Article 111736"},"PeriodicalIF":2.1,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142146929","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":"Assessment of oxidative status, detoxification capacity and immune responsiveness in honey bees with ageing","authors":"Jelena Spremo ,&nbsp;Jelena Purać ,&nbsp;Tatjana Čelić ,&nbsp;Srđana Đorđievski ,&nbsp;Ivan Pihler ,&nbsp;Danijela Kojić ,&nbsp;Elvira Vukašinović","doi":"10.1016/j.cbpa.2024.111735","DOIUrl":"10.1016/j.cbpa.2024.111735","url":null,"abstract":"<div><p>The honey bee (<em>Apis mellifera</em> L.), as an eusocial insect species, is an important model organism in research focusing on ageing and longevity, due to prominent seasonal lifespan plasticity within the worker caste (summer and winter worker bees). In this study, we employed a screening approach to evaluate several molecular parameters, providing comprehensive insights into the antioxidative (superoxide dismutase and catalase activity, reduced glutathione and sulfhydryl group content, total antioxidative capacity), detoxifying (glutathione <em>S</em>-transferase and acetylcholinesterase activity), and immune (phenol oxidase and glucose oxidase activity) status, as well as vitellogenin content, in the summer and winter generation of honey bees, across ageing stages and in two body compartments: the whole abdomen and the head. Summer worker bees were collected weekly for six weeks, while winter bees were collected monthly for five months. The results of our study clearly indicate a reduced overall antioxidative capacity of older groups of worker bees from both generations, while the parameters of immune responsiveness mostly contributed to the separation between the two generations based on season rather than age categories. Detoxification ability appeared to be more susceptible to environmental factors. An age-dependent increase in vitellogenin content was recorded in the abdomen, but without seasonal differences. These findings provide an excellent starting point for further investigations into age-related changes, particularly within the context of honey bee sociality.</p></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"298 ","pages":"Article 111735"},"PeriodicalIF":2.1,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1095643324001624/pdfft?md5=369e7c638b385a71d168efb6cc49d070&pid=1-s2.0-S1095643324001624-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142134550","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hypoxia-acclimation adjusts skeletal muscle anaerobic metabolism and burst swim performance in a marine fish","authors":"Benjamin Negrete Jr ,&nbsp;Kerri Lynn Ackerly ,&nbsp;Andrew J. Esbaugh","doi":"10.1016/j.cbpa.2024.111734","DOIUrl":"10.1016/j.cbpa.2024.111734","url":null,"abstract":"<div><p>Red drum, <em>Sciaenops ocellatus</em>, are a marine teleost native to the Gulf of Mexico that routinely experiences periods of low oxygen (hypoxia). Recent work has demonstrated this species has the capacity to improve aerobic performance in hypoxia through respiratory acclimation. However, it remains unknown how hypoxia acclimation impacts anaerobic metabolism in red drum, and the consequences of exhaustive exercise and recovery. Juvenile fish were acclimated to normoxia (<em>n</em> = 15, DO 90.4 ± 6.42 %) or hypoxia (n = 15, DO 33.6 ± 7.2 %) for 8 days then sampled at three time points: at rest, after exercise, and after a 3 h recovery period. The resting time point was used to characterize the acclimated phenotype, while the remaining time points demonstrate how this phenotype responds to exhaustive exercise. Whole blood, red muscle, white muscle, and heart tissues were sampled for metabolites and enzyme activity. The resting phenotype was characterized by lower pH_e and changes to skeletal muscle ATP. Exhaustive exercise increased muscle lactate, and decreased phosphocreatine and ATP with no effect of acclimation. Interestingly, hypoxia-acclimated fish had higher pH_e and pH_i than control in all exercise time points. Red muscle ATP was lower in hypoxia-acclimated fish versus control at each sample period. Moreover, acclimated fish increased lactate dehydrogenase activity in the red muscle. Hypoxia acclimation increased white muscle ATP and hexokinase activity, a glycolytic enzyme. In a gait-transition swim test, hypoxia-acclimated fish recruited anaerobic-powered burst swimming at lower speeds in normoxia compared to control fish. These data suggest that acclimation increases reliance on anaerobic metabolism, and does not benefit recovery from exhaustive exercise.</p></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"297 ","pages":"Article 111734"},"PeriodicalIF":2.1,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1095643324001612/pdfft?md5=ac010c18efcaf63bfa338f59a9c706db&pid=1-s2.0-S1095643324001612-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142114973","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}