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

{"title":"Cardiovascular responses of embryonic alligator (Alligator mississippiensis) exposed to 10% O2 and sodium cyanide (NaCN), a chemoreflex-inducing compound","authors":"John Eme ,&nbsp;Gil Martinez Bautista ,&nbsp;Audrey Keneda ,&nbsp;Kevin Tate ,&nbsp;George Melancon ,&nbsp;Dane A. Crossley II","doi":"10.1016/j.cbpa.2025.111865","DOIUrl":"10.1016/j.cbpa.2025.111865","url":null,"abstract":"<div><div>The possibly interactive effects of changes in atmospheric respiratory gases (hypoxia or hypercapnia) <em>and</em> pharmacological chemoreceptor stimulation have not been assessed previously. We present a series of experimental protocols investigating embryonic alligators' capacity to modulate a cardiovascular neural chemoreflex response to a known chemoreceptor stimulant, sodium cyanide (NaCN). We incubated alligator embryos in 21 % (normoxia) and 10 % O₂ (hypoxia) beginning at 20 % of embryonic incubation, and at 70 % and 90 % of incubation we measured heart rate and blood pressure responses to NaCN. These NaCN responses also included examining the effects of NaCN after 1-h exposure to 10 % O₂., ganglionic blockade with hexamethonium chloride and α-adrenergic blockade with phentolamine. Injections of NaCN into the chorioallantoic artery caused a rapid bradycardia followed by a secondary hypertension, which can be attributed to an autonomic nervous system mediated reflex loop. We compared the heart rate response to injections of 1 mg kg⁻¹ NaCN before and after a 1-h 10 % O₂ exposure, and it was clear that embryonic alligators lacked capacity to change the intensity of cardiovascular responses to this compound. Hexamethonium greatly lessened the rapid bradycardia, and at 90 % of incubation, the secondary hypertensive response to NaCN appeared due to α-adrenergic stimulation, as phentolamine lessened the response. Collectively, data indicate that while a cardiovascular chemoreflex can be induced by NaCN, the heart rate response lacks plasticity and is not modulated by hypoxic incubation in embryonic alligators.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"305 ","pages":"Article 111865"},"PeriodicalIF":2.1,"publicationDate":"2025-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143833810","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":"Adjustments to energy provisioning and oxidative balance in response to temperature in a wild passerine","authors":"Pierre Deviche ,&nbsp;Karen Sweazea ,&nbsp;Nadia Upah","doi":"10.1016/j.cbpa.2025.111864","DOIUrl":"10.1016/j.cbpa.2025.111864","url":null,"abstract":"<div><div>Climate change and urbanization are associated with elevated ambient temperature (T_a). This increase may negatively impact organisms by creating conditions that are outside their resilience limits, but the physiological mechanisms that limit phenotypic plasticity in response to T_a variation remain poorly understood. We investigated these mechanisms in captive House Finches, <em>Haemorhous mexicanus</em>, a common native resident of rural and urban environments. We exposed finches to temperatures either slightly below the species' lower critical temperature (constant 20 °C; COOL group) or close to its upper critical temperature (daily min. 27 °C, daily max. 35 °C; WARM group) for two weeks. Birds in the COOL group ate more than birds in the WARM group, which is consistent with the prediction that cool T_a exposure increased the metabolic rate. However, finches of the two groups did not differ with regard to their body masses, fat reserves, or blood concentrations of ketone bodies, uric acid, and erythrocytic peroxidized lipids. Thus, exposure to the two experimental treatments did not result in major metabolic differences between groups. Acute stress caused by handling and restraint for 30 min decreased plasma uric acid, which may have been associated with its utilization as a free radical scavenger and so may have decreased stress-associated oxidative damage. Acute stress also increased plasma ketone bodies, suggesting increased lipid oxidation. These stress-related metabolic changes did not differ in the COOL and WARM groups, indicating within the range of T_a to which birds were exposed that temperature did not affect the birds' physiological sensitivity to acute stress.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"305 ","pages":"Article 111864"},"PeriodicalIF":2.1,"publicationDate":"2025-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143791680","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":"Respiratory flow and tidal volume scale with body mass in sea turtles but not breath duration","authors":"Kino Sakai ,&nbsp;Tomoko Narazaki ,&nbsp;Masanori Mori ,&nbsp;Tomomi Matsumoto ,&nbsp;Kagari Aoki ,&nbsp;Andreas Fahlman ,&nbsp;Kentaro Q. Sakamoto","doi":"10.1016/j.cbpa.2025.111855","DOIUrl":"10.1016/j.cbpa.2025.111855","url":null,"abstract":"<div><div>The ventilatory capacity of sea turtles is an important factor in their diving ability because they spend most of their time submerged. However, there is limited information on the relationship between the ventilatory capacity and body mass of sea turtles. To investigate the allometric scaling of the functional ventilatory capacity, we measured respiratory flow, tidal volume, and breath duration of spontaneous breaths in 40 sea turtles from 3 species (loggerhead, <em>Caretta caretta</em>; green, <em>Chelonia mydas</em>; hawksbill, <em>Eretmochelys imbricata</em>) of various body sizes (range: 0.7–120.6 kg) on land and in water. The results showed that the ventilatory capacity did not differ on land or in water. The respiratory flow and tidal volume increased with body mass with an allometric exponent of 0.76–0.80 and 0.87–0.89, respectively. In contrast, the breath duration and the ratio of tidal volume to the maximum lung volume were constant. These results suggest that sea turtles increase respiratory flow by increasing tidal volume with increasing body mass rather than prolonging breath duration, which may allow them to reduce the surface interval to breathe. This study improves the understanding of the ventilatory capacity of sea turtles.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"305 ","pages":"Article 111855"},"PeriodicalIF":2.1,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143797223","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 histological and molecular response of acute hypoxia and reoxygenation in rainbow trout and steelhead","authors":"Xiao-Qun Chen ,&nbsp;Yan-Gen Zhou ,&nbsp;Kun-Tong Jia ,&nbsp;Yu-Hang Wang ,&nbsp;Zhen Zhao ,&nbsp;Yue-Huan Zhang ,&nbsp;Zhi-Tao Huang ,&nbsp;Qin-Feng Gao ,&nbsp;Yun-Wei Dong ,&nbsp;Shuang-Lin Dong","doi":"10.1016/j.cbpa.2025.111854","DOIUrl":"10.1016/j.cbpa.2025.111854","url":null,"abstract":"<div><div>Hypoxia is a critical environmental stressor affecting fish survival and physiological function. Landlocked rainbow trout (<em>Oncorhynchus mykiss</em>) and anadromous steelhead (<em>Oncorhynchus mykiss</em>), two ecotypes of the same species, exhibit distinct physiological adaptations to fluctuating oxygen levels. To investigate their responses to acute hypoxia in these fish, brain histology and transcriptome analyses were conducted before stress, after hypoxia (12 and 24 h), and after reoxygenation (24 h). The results showed that the number of vacuolated nerve cells in the brain increased with the duration of hypoxia and decreased after 24 h of reoxygenation in both fish. RNA-Seq analysis identified 8409 differentially expressed genes (3952 in rainbow trout and 4457 in steelhead), one hypoxia-related module (MEred), and two significantly expressed gene clusters (cluster 3 in rainbow trout and cluster 8 in steelhead) through differential expression analysis, weighted gene co-expression network analysis (WGCNA), and Mfuzz clustering. KEGG pathway enrichment analysis revealed that signal transduction, immune response, angiogenesis, and apoptosis were significantly influenced by hypoxia in both fish. Distinct hypoxic responses were observed: in rainbow trout, ferroptosis, necroptosis, phosphatidylinositol signaling, calcium, and apelin signaling pathways were enriched, whereas in steelhead, the enriched pathways included platelet activation, Rap1, PI3K-Akt, Hippo, relaxin, and oxytocin signaling. Steelhead display marginally greater hypoxia tolerance than rainbow trout, although the difference is minimal, likely owing to their classification as the same species. These findings provide insight into the physiological and molecular mechanisms underlying hypoxia and reoxygenation stress in salmonids, contributing to a broader understanding of oxygen homeostasis in fish.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"305 ","pages":"Article 111854"},"PeriodicalIF":2.1,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143789429","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":"Novel mechanisms of epithelial ion transport and its regulation","authors":"Dennis Kolosov ,&nbsp;Sima Jonusaite","doi":"10.1016/j.cbpa.2025.111852","DOIUrl":"10.1016/j.cbpa.2025.111852","url":null,"abstract":"","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"305 ","pages":"Article 111852"},"PeriodicalIF":2.1,"publicationDate":"2025-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143761144","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":"Feeding time modulates the daily rhythms of expression of digestive and metabolic enzymes in the liver, and food intake regulation and reward systems in the hypothalamus of the European sea bass (Dicentrarchus labrax)","authors":"Elisa Samorì ,&nbsp;Inmaculada Rodríguez ,&nbsp;José Antonio Paullada-Salmerón ,&nbsp;José Antonio Muñoz-Cueto ,&nbsp;Verónica González-Nunez ,&nbsp;Francisco Javier Sánchez-Vázquez ,&nbsp;José Fernando López-Olmeda","doi":"10.1016/j.cbpa.2025.111853","DOIUrl":"10.1016/j.cbpa.2025.111853","url":null,"abstract":"<div><div>Fish exhibit daily rhythms at the molecular level across different tissues, synchronized by <em>zeitgebers</em>, such as food availability. To optimize feeding, organisms align internal timekeeping systems to environmental cues. Previous studies on intermediary metabolism and the hypothalamic control of food intake in fish have underscored the significance of feeding time and daily rhythms. This study examined how feeding times—mid-light (ML) <em>versus</em> mid-dark (MD)—influence the rhythmic transcription of digestive and metabolic enzymes in the liver, and regulatory factors of food intake in the hypothalamus of European sea bass (<em>Dicentrarchus labrax</em>). It also explored the connection between food intake control and the reward system. When fish were fed at ML, genes involved in protein digestion (<em>tryp2, tryp3, ctrl,</em> and <em>cpa5</em>) exhibited daily rhythms with peaks early in the dark phase (ZT 11:17–13:36). These peaks were delayed in MD-fed fish (ZT 16:57–18:27). <em>Pla2</em>, a gene related to lipid metabolism, and transamination genes (<em>c-alt</em>, <em>m-alt</em>) showed rhythms only in ML-fed fish, with acrophases in the light phase (ZT 5:01–13:58), such as pyruvate kinase (<em>pk</em>) that peaked at ZT 6:16. Orexigenic genes (<em>npy, orexin</em>) had rhythms only in the MD group, with nocturnal peaks (ZT 13:09, 16:06). Conversely, reward system genes (<em>th, bdnf</em>) were rhythmic in ML-fed fish (ZT 17:35, 11:46), with only <em>th</em> retaining its rhythm in MD-fed fish (ZT 15:30). These findings suggest feeding time significantly affects rhythms in digestive and metabolic processes. They also highlight the intricate nature of food intake regulation systems, which present diverse synchronization patterns in relation to feeding time.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"305 ","pages":"Article 111853"},"PeriodicalIF":2.1,"publicationDate":"2025-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143756075","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":"Comparative analysis of differential gene expression in hepatopancreas of Chinese mitten crabs (Eriocheir sinensis) with different carapace colors","authors":"Qi Zhu ,&nbsp;Maolei Wei ,&nbsp;Xinxin Chen ,&nbsp;Xugan Wu ,&nbsp;Xiaowu Chen","doi":"10.1016/j.cbpa.2025.111851","DOIUrl":"10.1016/j.cbpa.2025.111851","url":null,"abstract":"<div><div>The carapace color of the Chinese mitten crab (<em>Eriocheir sinensis</em>) significantly influences consumer preference and market value, yet the underlying molecular mechanisms remain poorly understood. In this study, transcriptome sequencing coupled with weighted gene co-expression network analysis (WGCNA) was employed to elucidate genetic and metabolic pathways involved in three genetically distinct carapace color phenotypes (red, white, and green). Hepatopancreatic transcriptome analyses across these color variants identified 910, 1555, and 1598 differentially expressed genes (DEGs) in pairwise comparisons. Functional enrichment analyses revealed significant activation of oxidoreductase activity, retinol metabolism, and mitochondrial energy metabolism pathways in crabs with red carapaces. Notably, key pigmentation-associated genes, including <em>ninaB</em> (carotenoid isomerase) and <em>sno1</em> (flavin monooxygenase), were markedly upregulated. Additionally, WGCNA identified a highly correlated (<em>r</em> = 0.97) red-specific gene module enriched predominantly with oxidative phosphorylation-related genes, such as <em>atpsycf6</em> and <em>ndufb4</em>, emphasizing the energetic investment associated with pigment biosynthesis. Furthermore, retinol metabolism emerged as a pivotal pathway connecting carotenoid processes with immune and antioxidant functions, implying potential physiological trade-offs between pigmentation and stress resilience. Overall, this study advances our understanding of crustacean carapace coloration mechanisms and provides valuable genetic targets for selective breeding aimed at enhancing desirable color traits in <em>E. sinensis</em>.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"305 ","pages":"Article 111851"},"PeriodicalIF":2.1,"publicationDate":"2025-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143747069","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":"Transcriptome analysis and CRISPR-Cas9-mediated mutagenesis identify gpr116 as a candidate gene for growth promotion in grass carp (Ctenopharyngodon idella)","authors":"Tao Sheng ,&nbsp;Xin-Zhan Meng ,&nbsp;Qiaozhen Yu ,&nbsp;Wenyao Lv ,&nbsp;Yuxuan Chen ,&nbsp;Qian Cong ,&nbsp;Weizhong Li ,&nbsp;Lang Gui ,&nbsp;Jiale Li ,&nbsp;Xiaoyan Xu","doi":"10.1016/j.cbpa.2025.111850","DOIUrl":"10.1016/j.cbpa.2025.111850","url":null,"abstract":"<div><div>Grass carp (<em>Ctenopharyngodon idella</em>) is an economically important aquaculture species known for its considerable variability in growth performance. In this study, we investigated the growth phenotype by comparing fast-growing and slow-growing groups. Microstructural analyses revealed that slow-growing fish exhibited significantly larger myofibrillar gaps and lower muscle fiber density. To elucidate the underlying molecular basis, we performed transcriptome (RNA-Seq) analysis of brain and dorsal muscle tissues. 328 differentially expressed genes (DEGs) were identified in dorsal muscle tissue (33 up and 295 down-regulated) and 228 in brain tissue (17 up and 211 down-regulated). Gene Ontology and KEGG enrichment analyses indicated that the DEGs were closely associated with apoptosis and angiogenesis pathways. Among the candidate genes, <em>gpr116</em> was significantly up-regulated in the brain and dorsal muscle tissue of the fast-growing group. Finally, CRISPR-Cas9-mediated knockout in a zebrafish model confirmed that <em>gpr116</em> deletion significantly restricted growth, underscoring its pivotal role in the growth regulation of grass carp. These discoveries lay significant groundwork for deeper exploration of growth regulation mechanisms in grass carp and offer important clues for selective breeding of key growth marker genes in this species.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"305 ","pages":"Article 111850"},"PeriodicalIF":2.1,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143756077","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":"Triaxial accelerometers and subcutaneous biologgers as tools to record diurnal and nocturnal changes in locomotor activity, body temperature, heart rate, and heart rate variability in melatonin-treated lambs (Ovis aries)","authors":"José A. Abecia ,&nbsp;Isabella Manenti ,&nbsp;Irene Viola ,&nbsp;Paola Toschi ,&nbsp;Carlos Palacios ,&nbsp;Francisco Canto ,&nbsp;Silvia Miretti","doi":"10.1016/j.cbpa.2025.111849","DOIUrl":"10.1016/j.cbpa.2025.111849","url":null,"abstract":"<div><div>The study of growth and development of lambs <em>(Ovis aries)</em> is essential in sheep farming, and melatonin plays an important role in the physiology of growing lambs. The effects of an exogenous melatonin treatment on several physiological characteristics in fattening lambs at weaning were studied. Eight lambs were assigned to one of two groups; those that did (melatonin group, <em>n</em> = 4) or did not (no-melatonin group, n = 4) receive two subcutaneous melatonin implants at weaning. At the end of the fattening period, to quantify locomotor activity (LA), each lamb was fitted with a triaxial accelerometer, for 7 days. Simultaneously, lambs received a surgically implanted subcutaneous temperature (T) and heart rate (HR) biologger, which was programmed to record data every 5 min. HR variability (HRV) variables (SDNN, the standard deviation of normal-to-normal R-R intervals, and RMSSD, the root mean square of consecutive deviations between normal heartbeats) were measured. All of the variables exhibited 24-h circadian rhythms. Time of day (daytime vs. nighttime) had a significant effect on LA, T, and HR, but considering both treatment with melatonin and time, differences between time for these variables were only observed in melatonin-treated lambs. Exogenous melatonin did not affect LA or T, but melatonin-treated lambs had lower HR, SDNN, and RMSSD than did non-treated lambs. In conclusion, the use of subcutaneous biologgers and triaxial accelerometers in growing lambs demonstrated circadian rhythms in LA, T, HR, and HRV, and melatonin treatment negatively affected HRV, but its effects on the other physiological variables differed between day and night.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"305 ","pages":"Article 111849"},"PeriodicalIF":2.1,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143726084","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":"Commentary: Cellular functions of vitamin D-binding protein","authors":"David R. Fraser ,&nbsp;Rebecca S. Mason","doi":"10.1016/j.cbpa.2025.111848","DOIUrl":"10.1016/j.cbpa.2025.111848","url":null,"abstract":"<div><div>The classical roles of plasma vitamin D-binding protein (DBP) are the transport of vitamin D and its metabolites in blood, as well as because of its actin-binding affinity, the removal of any actin that escapes into the circulation when cells are damaged or destroyed. It is also apparent that DBP has functions related to the activity of lymphoid cells that are independent of its role as a vehicle for delivering vitamin D metabolites around the body. A separate major function of DBP was revealed with the discovery of the endocytic activity of cell membrane proteins megalin and cubilin, in internalizing DBP into cells in a number of different organs, particularly the kidney and skeletal muscle. Within a cell, DBP binds specifically to cytoplasmic actin filaments. Because most DBP in plasma is in the apo-configuration, that which binds to actin within specific cells, provides an array of empty binding sites that enable free 25-hydroxyvitamin D (25(OH)D), that diffuses into those cells, to be retained on the DBP-actin structure. The retention of 25(OH)D diffusing into renal proximal tubule cells provides the substrate, after DBP proteolysis, for the 1-hydroxylase which generates the vitamin D hormone, 1,25-dihydroxyvitamin D (1,25(OH)₂D). In skeletal muscle cells, the 25(OH)D that accumulates on the internalized DBP-actin complex, diffuses back to the circulation when that DBP undergoes proteolysis. This diffusion of 25(OH)D into and out of skeletal muscle cells, mediated by the internalized apo-DBP mechanism, accounts for the long half-life of 25(OH)D in the circulation and the role this process plays in maintaining vitamin D status.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"305 ","pages":"Article 111848"},"PeriodicalIF":2.1,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143714519","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}