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

{"title":"The Captive Gut: the impacts of long-term captivity on the intestinal digestive enzyme activities of a marine herbivorous fish","authors":"Jordan E. Buckner ,&nbsp;Leyna Vo ,&nbsp;Michelle J. Herrera ,&nbsp;Karina Brocco French,&nbsp;Daniel R. Rankins,&nbsp;Jacqueline Vasquez,&nbsp;Asmita Pande,&nbsp;Kwasi M. Connor,&nbsp;Valentina I. Peña Gonzalez,&nbsp;Donovan P. German","doi":"10.1016/j.cbpa.2025.111965","DOIUrl":"10.1016/j.cbpa.2025.111965","url":null,"abstract":"<div><div>Given that digestion is largely a chemical process in fishes that do not masticate or triturate their food, digestive enzyme activities are frequently measured as indicators of what nutrients a fish can readily digest. Here, we explored what happens to digestive tract length and digestive enzyme activities in a marine herbivorous fish (<em>Xiphister mucosus</em>) fed in captivity for more than two years. Captivity is known to impact nearly all aspects of an animal's biology, but the gut microbiome has received more attention than digestive biochemistry in this regard. After consuming a prepared diet primarily composed of algae collected from the same site from which the fish were collected for over two years, the lab-fed fish showed a marked reduction in amylase, trypsin, and aminopeptidase activities in comparison to wild-caught fish. Moreover, the gradient of activity moving along the intestine (activities decreasing distally for amylase and trypsin, increasing for aminopeptidase) completely disappeared in the lab-fed fish. The relative gut length decreased by about 18 % in the lab-fed fish, suggesting that they ate less than their wild counterparts, which likely led to slower gut transit and more time for enzymes to interact with substrates. Hence, digestive enzyme activities were lower in the lab-fed fish. A formulated diet in the laboratory presents a different gut environment for the herbivorous <em>X. mucosus</em>, and perhaps feeding them a live algal diet would better replicate the wild-gut phenotype if this fish is to be held for lengthy periods of time for display or aquaculture purposes.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"312 ","pages":"Article 111965"},"PeriodicalIF":2.2,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145806480","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":"Tissue-specific markers of salinity-induced allostasis in the very euryhaline and widespread mussel Mytilus galloprovincialis","authors":"Nicole Stakowian ,&nbsp;Marta Cunha ,&nbsp;Rosa Freitas ,&nbsp;Carolina A. Freire","doi":"10.1016/j.cbpa.2025.111954","DOIUrl":"10.1016/j.cbpa.2025.111954","url":null,"abstract":"<div><div>Environmental salinity is one of the main factors causing osmotic stress in coastal bivalves, influencing their physiological performance and distribution. The Mediterranean mussel <em>Mytilus galloprovincialis</em> is one of the most euryhaline marine invertebrates, tolerating large salinity fluctuations throughout its wide geographical distribution. This study investigated how different tissues respond to different salinities, identifying potential biochemical markers of tolerance and plasticity. Mussels were exposed for 14 and 28 days to the salinities 20, 25, 30, 35, and 40, and biomarkers related to metabolism, antioxidant and biotransformation systems, cellular damage, and neurotoxicity were analyzed in the digestive gland, gills, mantle, and muscle. The digestive gland showed significant modulation of succinate dehydrogenase, superoxide dismutase and carboxylesterases activities, glycogen content, and antioxidant capacity, demonstrating its metabolic and antioxidant role. The gills showed changes in glutathione S-transferases, acetylcholinesterase, and lipid peroxidation levels, particularly under hyposaline (20) and hypersaline (40) conditions. Mantle and muscle showed lower responsiveness to the tested salinities. Biochemical responses at salinities between 25 and 35 indicated the activation of allostatic mechanisms assuring survival and damage prevention. The results corroborate the concept of salinity-induced allostasis as a mechanism of resistance in osmoconforming euryhaline bivalves. Furthermore, they highlight the importance of functional compartmentalization among tissues in responding to osmotic challenges. The results also support the use of organ-level biomarkers to assess physiological resistance to salinity gradients in coastal environments.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"311 ","pages":"Article 111954"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145535155","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 effects of tidally changing salinities on branchial tight junction protein gene expression in tilapia","authors":"G.H.T. Malintha ,&nbsp;Ke Cao ,&nbsp;Fritzie T. Celino-Brady ,&nbsp;Jason P. Breves ,&nbsp;Andre P. Seale","doi":"10.1016/j.cbpa.2025.111956","DOIUrl":"10.1016/j.cbpa.2025.111956","url":null,"abstract":"<div><div>To maintain hydromineral balance during transitions between different environmental salinities, euryhaline teleosts adjust the permeability characteristics of their surface epithelia to align with ambient conditions. Tight junctions (TJs), which form the apical-lateral barriers between epithelial cells, control the paracellular movement of solutes and water. Consequently, euryhaline species must efficiently reorganize branchial TJs when acclimating to freshwater (FW) and seawater (SW) environments. However, little is known about how TJs are regulated under tidally changing salinities. In the current study, we employed RNA-Seq to identify several branchial TJ transcripts that are differentially expressed in Mozambique tilapia (<em>Oreochromis mossambicus</em>) acclimated to FW, SW, or a tidal regime (TR). The most abundant and differentially expressed TJ transcripts, which included claudins (<em>cldn-4 like</em>, <em>cldn7b</em>, <em>cldn23a</em>, and <em>cldn-like ZF-A89</em>), occludins (<em>oclna</em> and <em>oclnb</em>), and TJ proteins (<em>tjp1a</em> and <em>tjp3</em>), were further investigated by qPCR. Generally, the expression of TJ transcripts varied to a greater extent between the FW and SW phases of the TR (denoted TF and TS, respectively) than between steady-state FW and SW conditions. Furthermore, TJ transcripts were usually upregulated in TF compared to TS or SW controls. In contrast, the gene expression of branchial ion transporters did not change as markedly under a TR. Together, these results suggest that TJs play a crucial role in regulating the permeability of branchial epithelia by preventing ion loss in hyposmotic conditions, particularly during short-term tidally changing salinities.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"311 ","pages":"Article 111956"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145607606","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":"Temporal changes in Gpdh1 expression in Bombyx mori: its correlation with embryonic diapause initiation and maternal modulation via insulin and sugar metabolism","authors":"Shi-Hong Gu,&nbsp;Pei-Ling Lin","doi":"10.1016/j.cbpa.2025.111943","DOIUrl":"10.1016/j.cbpa.2025.111943","url":null,"abstract":"<div><div>Cytosolic NAD-dependent glycerol-3-phosphate dehydrogenases (GPDHs) catalyze the reduction of dihydroxyacetone phosphate (DHAP) to glycerol-3-phosphate using NADH, representing the first step in the glycerol biosynthesis pathway. While it is well established that the onset of egg diapause in <em>Bombyx mori</em> is accompanied by the rapid conversion of glycogen into sorbitol and glycerol, the regulation of <em>Gpdh1</em> gene expression during embryonic diapause remains less well understood. In the present study, we investigated changes in the expression levels of the <em>Gpdh1</em> gene. In diapause eggs, <em>Gpdh1</em> expression remained relatively high during the first three days after oviposition, then gradually declined. In contrast, HCl-treated developing eggs exhibited an abrupt decrease in <em>Gpdh1</em> expression upon treatment, followed by persistently low levels. Non-diapause eggs exhibited a similarly abrupt decrease as observed in HCl-treated eggs, indicating a correlation between the sharp decrease in <em>Gpdh1</em> expression and embryonic development. To further explore the potential mechanisms regulating <em>Gpdh1</em> expression, we analyzed the expression of several genes—including <em>Gpdh1</em>, insulin signaling (<em>bombyxin-A6</em> and <em>-Z1</em>), sugar transporters (<em>Tret1</em>, <em>St1</em>, <em>St3</em>, <em>St4</em>, and <em>St5</em>), and trehalases (<em>Treh1</em> and <em>Treh2</em>)—in the mother ovaries during the pupal stage of diapause- and non-diapause-destined silkworms. Our results showed that the expression of <em>Gpdh1</em>, <em>bombyxin-Z1</em>, <em>Tret1</em>, and <em>Treh2</em> genes in diapause-destined ovaries increased in a stage-dependent manner compared to non-diapause-destined ovaries. In contrast, diapause-destined mother ovaries exhibited significantly lower expression levels of <em>bombyxin-A6</em>, indicating reduced insulin signaling during the pupal stage. Our findings suggest that reduced insulin signaling, along with elevated expression of <em>Gpdh1</em>, <em>bombyxin-Z1</em>, <em>Tret1</em>, and <em>Treh2</em> genes may promote glycogen accumulation in the ovaries of diapause-destined mothers during the pupal stage. This accumulation could, in turn, lead to increased <em>Gpdh1</em> gene expression in diapause eggs laid by these mothers, thereby contributing to the initiation of diapause.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"311 ","pages":"Article 111943"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145330932","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":"Body mass shapes mitochondrial NADH and NADPH sources in mammalian skeletal muscle","authors":"Mélanie Boël ,&nbsp;Yann Voituron ,&nbsp;Damien Roussel","doi":"10.1016/j.cbpa.2025.111944","DOIUrl":"10.1016/j.cbpa.2025.111944","url":null,"abstract":"<div><div>Here, we investigate whether the elevated mitochondrial H₂O₂ release in small mammals arises from a tradeoff between NAD-dependent enzymes, which synthesizes NADH to support high oxidative phosphorylation, and NADP-dependent enzymes, which generates NADPH to detoxify H₂O₂ within the matrix. We measured the activities of NAD- and NADP-dependent enzymes in skeletal muscle mitochondria from mammal species ranging from 4 g to 600 kg. The activities of the two most active NADPH-producing enzymes increased, whereas NAD-dependent enzyme activities declined with body mass. Therefore, small mammals prioritize NADH synthesis at the expense of NADPH, increasing the oxidative cost of mitochondrial metabolism.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"311 ","pages":"Article 111944"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145425632","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 chronic salinity stress on growth performance, physiological response and intestinal microbiota of largemouth bass (Micropterus salmoides)","authors":"Yang Liu ,&nbsp;Jing Tian ,&nbsp;Shengjie Li ,&nbsp;Tao Zhu ,&nbsp;Jinxing Du ,&nbsp;Caixia Lei ,&nbsp;Linqiang Han ,&nbsp;Hongmei Song","doi":"10.1016/j.cbpa.2025.111945","DOIUrl":"10.1016/j.cbpa.2025.111945","url":null,"abstract":"<div><div>To address the critical shortage of freshwater in global fisheries, the cultivation of largemouth bass (<em>Micropterus salmoides</em>) using geographically widespread saline-alkaline water is a viable resource alternative. In the present study, we systematically investigated the effects of chronic salinity stress (180 days, 9 ppt) on the growth performance, osmoregulation, antioxidant capacity, digestion capacity, and intestinal microbiota of largemouth bass. The results showed that the growth performance (CF, ADG, and SGR) of largemouth bass in the saltwater group decreased significantly compared with the freshwater group after 180 days of culture. The osmoregulation capacity (serum osmolality, serum cortisol, NKA, and CMA) and antioxidant capacity (SOD, CAT, MDA, ACP, AKP, and GSH-Px) in the saltwater group were significantly higher than those in the freshwater group at 60d, 120d, and 180d (<em>P</em> &lt; 0.05). Histological analysis showed that chlorine cells and macrophages proliferated in the gill and liver of the saltwater group. Additionally, trypsin and pancreatic lipase levels in the saltwater group peaked on 180 days, but remained significantly lower than those in the freshwater group (<em>P</em> &lt; 0.05). According to intestinal microbiota analysis, the relative abundance of Bacillus and Cetobacterium in the saltwater group was significantly higher than that in the freshwater group (<em>P</em> &lt; 0.05). The above results indicated that largemouth bass showed excellent stress resistance in the face of chronic salinity stress, which could be used as a saline-alkali culture species. The work provides new insights for the study of salt tolerance in freshwater fish and promotes the utilization of saline-alkali water.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"311 ","pages":"Article 111945"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145477262","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":"Seasonal adjustments of basal metabolism and substrate metabolism in an Asian passerine bird, the red-billed leiothrix","authors":"Xing-Rong He ,&nbsp;Xiao-Lin Zhu ,&nbsp;Zi-Qing Gao ,&nbsp;Qi Zheng ,&nbsp;Shou-Hui Wang ,&nbsp;Zhe Wang ,&nbsp;Ming Li ,&nbsp;Jin-Song Liu","doi":"10.1016/j.cbpa.2025.111950","DOIUrl":"10.1016/j.cbpa.2025.111950","url":null,"abstract":"<div><div>Phenotypic flexibility enables organisms like birds to adapt to environmental changes, particularly through physiological adjustments such as basal metabolism in response to temperature fluctuations. We have previously reported that red-billed leiothrix (<em>Leiothrix lutea</em>) increases basal metabolism when acclimated to cold temperatures in the lab. This study investigated whether similar physiological changes also occur in response to seasonal variations in the wild. Red-billed leiothrixes were captured in different seasons in Wenzhou and subjected to experiments that measured body mass, metabolic parameters such as basal metabolic rate (BMR), cytochrome <em>c</em> oxidase (COX), substrates of metabolism such as serum glucose, hepatic glycogen, and muscle glycogen, triglyceride (TG), free fatty acid (FFA), enzymes such as carnitine palmitoyl transferase-1 (CPT-1), β-hydroxyacyl Co-A dehydrogenase (HOAD), and citrate synthase (CS), and thyroid hormones (T₄, thyroxine, and T₃, triiodothyronine). In winter, the birds showed significant increases in body mass, BMR, and COX activity in the liver and kidney compared to summer. Additionally, serum TG, concentration of CPT-1 and HOAD in the liver, serum glucose, and muscle glycogen were also elevated. These results were consistent with enhanced metabolism and higher consumption of lipids by red-billed leiothrixes during winter compared with other seasons. Therefore, red-billed leiothrixes show the same pattern of phenotypic flexibility as thermally acclimated birds in the lab. This study provides valuable data for understanding basal metabolism in small birds in response to seasonal changes.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"311 ","pages":"Article 111950"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145484000","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":"Context-dependent relationships between metabolism and behavior across temperature acclimations in sheepshead minnows (Cyprinodon variegatus)","authors":"Madison Schumm,&nbsp;Kerri L. Ackerly,&nbsp;Andrew J. Esbaugh","doi":"10.1016/j.cbpa.2025.111952","DOIUrl":"10.1016/j.cbpa.2025.111952","url":null,"abstract":"<div><div>Marine fish are able to cope with environmental changes through altering their physiology and behavior. Among environmental stressors, thermal stress is particularly relevant for fish because increased temperature leads to elevated baseline metabolic costs and also has known impacts on behavior. The Performance Model provides a conceptual framework linking metabolism and behavior such that individual differences in baseline metabolic demand influence behavioral expression specifically related to acquiring resources that support metabolic machinery. Thus, under warming, increased energy demand should lead to increased risk-taking and lower behaviors that deter predation (e.g., shoaling and scototaxis). On this background, our objective was to assess behavioral and metabolic responses to warming and the relationship these traits across two temperatures in an estuarine model teleost, the sheepshead minnow (<em>Cyprinodon variegatus</em>). Fish were exposed to 22 °C or 32 °C for 14-days and standard metabolic rate (SMR) was measured. Each fish was subsequently tested in a series of behavioral assays to assess activity, exploration, sociability, and anxiety-like behavior. As anticipated, warmer temperatures increased in SMR and increased activity while reducing anxiety-like behavior. However, relationships between behavior and metabolism were present only in control conditions and, composite behavioral scores indicated negative relationships in in the opposite direction of predictions based on the performance model. Interestingly, trait patterns dissipated under warming suggesting that predictions based on models in control conditions may have dubious utility under climate change. We argue that behavioral-metabolic relationships are sensitive to context, and environmental factors should be considered when exploring the intersection between behavior and physiology.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"311 ","pages":"Article 111952"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145558325","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":"Heat shock protein 70 expression in the skin of Pelophylax bergeri in response to thermal stress","authors":"Francesca Simoncelli ,&nbsp;Ines Di Rosa ,&nbsp;Anna Fagotti","doi":"10.1016/j.cbpa.2025.111955","DOIUrl":"10.1016/j.cbpa.2025.111955","url":null,"abstract":"<div><div>The amphibian skin is an organ of interest as an indicator of the cellular response to stress factors. The upregulation of Heat Shock Proteins (HSPs) is an important step in the cellular defense mechanisms against various endogenous and exogenous stressors. In this preliminary note, we investigated the expression of the inducible Hsp70 as a marker of thermal stress in the skin of the anuran <em>Pelophylax bergeri</em>. RT-qPCR analysis revealed that there was an elevated upregulation in the expression levels of Hsp70 after short-term heat stress. The immunolocalization of Hsp70 on skin samples shocked at 33 °C, showing the highest gene induction, revealed a positive staining in both epithelial and connective skin cells. These results indicate that Hsp70 could be a potential player in the skin defense mechanism. This study might contribute to a better understanding of the stress response in amphibians against thermal shock.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"311 ","pages":"Article 111955"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145551872","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":"Key indicators of metabolic activity in the long-tailed ground squirrels, (Urocitellus undulatus) in different functional states","authors":"Polina O. Teplova ,&nbsp;Ekaterina V. Kuznetsova ,&nbsp;Aleksandra V. Gorbunova ,&nbsp;Liubov N. Markevich ,&nbsp;Nadezhda M. Zakharova","doi":"10.1016/j.cbpa.2025.111953","DOIUrl":"10.1016/j.cbpa.2025.111953","url":null,"abstract":"<div><div>The aim of this study is to examine the seasonal strategies employed by obligate hibernators, such as long-tailed ground squirrels (<em>Urocitellus undulatus</em>), for metabolic maintenance at various levels of organization. To this end, we conducted a comprehensive evaluation encompassing respirometry, histological and biochemical analysis of the thyroid gland, examination of neutral and phospholipid content in brown adipose tissue, and biochemical assessment of the blood lipid profile. Our results revealed pronounced variations in metabolic parameters on a seasonal basis. In the fall (pre-hibernation), <em>U. undulatus</em> exhibited an increase in respiratory metabolism ranging from 1.4 to 1.7 times compared to the summer control group. It is accompanied with an augmentation in the functional activity of the thyroid gland, an increase in all fractions of phospholipids in brown adipose tissue, and an elevation in the level of lipase in the blood. Concurrently, there is a decline in di- and triglyceride levels in brown fat. In a state of torpor, there was an observed increase in the growth of certain indicators (lipids, thyroid hormones, etc.), a particularly significant rise is observed for β-hydroxybutyrate. In the interbout euthermia, a recovery of nearly all indicators to summer-fall values was observed. These findings hold potential relevance for a better understanding of metabolic disorders and adaptations to extreme conditions.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"311 ","pages":"Article 111953"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145544008","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}