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

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

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

{"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":"2025-09-16","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":"Integrated analysis of antioxidant defense and energy metabolism in the gills of Sinonovacula constricta under hyposalinity stress","authors":"Yuting Han ,&nbsp;Kai Ye ,&nbsp;Geqi Gao ,&nbsp;Jinxu Guo ,&nbsp;Ming Shan ,&nbsp;Donghong Niu","doi":"10.1016/j.cbpa.2025.111932","DOIUrl":"10.1016/j.cbpa.2025.111932","url":null,"abstract":"<div><div>Salinity has a significant impact on the growth, energy metabolism, and immune regulation of marine bivalves. To elucidate the response of marine bivalves to low salinity environments and their tolerance mechanisms, this study investigated histopathological alterations and measured oxidative stress indicators along with energy metabolism parameters in gill tissues of <em>Sinonovacula constricta</em> under hyposalinity stress (salinity 5). Transcriptomic profiling of gills from the control group (salinity 20) and low salinity group was concurrently analyzed. The results demonstrated that during the initial stress phase, the antioxidant defense system was activated, evidenced by significant increases in superoxide dismutase (SOD) and catalase (CAT) activities as well as total antioxidant capacity (T-AOC). Concurrently, elevated levels of reactive oxygen species (ROS) and malondialdehyde (MDA) indicated oxidative stress status. In the later stress phase, declined activities of antioxidant enzymes suggested severe oxidative damage. Throughout hyposalinity exposure, ATP content progressively decreased, while ATPase and pyruvate kinase (PK) activities exhibited an initial increase followed by reduction, reflecting elevated energy expenditure. Transcriptomic analysis identified 501 differentially expressed genes (DEGs) between low salinity and control groups. GO and KEGG enrichment analyses revealed significant enrichment of these DEGs in energy metabolism and protein synthesis-related processes, with notable enrichment in functional enzyme activities associated with the phosphatidylinositol signaling pathway in gills. This study systematically revealed the physiological response mechanisms of <em>S. constricta</em> to hyposalinity stress, and elucidated the roles of the phosphatidylinositol signaling pathway, amino acid metabolism, and endoplasmic reticulum protein processing in the adaptation of <em>S. constricta</em> to hyposalinity stress.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"310 ","pages":"Article 111932"},"PeriodicalIF":2.2,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145088394","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":"Hypoxia and reoxygenation induced distinct patterns of response in antioxidant capacity between two cyprinid fish species","authors":"Qing-lin Cao,&nbsp;Shi-jian Fu,&nbsp;Yu-tong Hou,&nbsp;Shuai Yang,&nbsp;Zhong-hua Tang","doi":"10.1016/j.cbpa.2025.111928","DOIUrl":"10.1016/j.cbpa.2025.111928","url":null,"abstract":"<div><div>Antioxidant defense represents a critical biological capacity enabling organisms to counteract homeostasis disruption and mitigate oxidative stress induced by environmental stressors, such as oxygen fluctuations. However, comparative studies investigating the differential responses of antioxidant defense systems to oxygen fluctuations across diverse animal species remain limited. In the present study, two common cyprinid species—common carp (<em>Cyprinus carpio</em>) and Chinese hook snout carp (<em>Opsariichthys bidens</em>)—maintained under normoxic conditions (&gt; 7 mg L⁻¹ O₂) were exposed to hypoxia (1.04 ± 0.2 mg L⁻¹ O₂) for 3 h, followed by a 3-h reoxygenation period (&gt; 7 mg L⁻¹ O₂). A comparative analysis of key enzymes within the classical enzymatic antioxidant system was subsequently performed. The results demonstrated that the total protein (TP) concentration in the liver, brain and gill of both fish species was significantly altered under hypoxic and/or reoxygenation conditions. In common carp, hepatic superoxide dismutase (SOD) and total antioxidant capacity (T-AOC) activity, cerebral SOD, catalase (CAT) and glutathione peroxidase (GPx) activity, as well as branchial CAT and GPx activity, were significantly elevated during the hypoxic period. Except for hepatic SOD activtiy, which remained elevated during reoxygenation, these parameters recovered to control levels. These findings support the preparation for oxidative stress (POS). However, in Chinese hook snout carp, hepatic CAT and GPx activity, as well as branchial GPx and T-AOC activity, exhibited a distinct decreasing trend during hypoxia, followed by recovery to control levels during reoxygenation. Furthermore, cerebral SOD, T-AOC activity, along with branchial SOD activity, remained unchanged under hypoxic conditions but increased significantly during reoxygenation. These responses did not align with the POS strategy. The malondialdehyde (MDA) content remained stable or decreased in both tested fish species during hypoxia and reoxygenation, except for an increase in MDA levels under hypoxic conditions. The result indicates that neither species experienced oxidative damage. These results suggest that the common carp tends to employ a proactive strategy to cope with environmental stress. The tendency may be associated with its frequent exposure to adverse environmental conditions, which has likely facilitated the development of enhanced hypoxia tolerance and the capacity to anticipate future stressors. In contrast, the Chinese hook snout carp, which exhibits lower hypoxia-tolerant, inhabits rapid-flowing habitats where dissolved oxygen concentrations remain relatively high and stable. This has suppressed the development of capacities for predict future changes in environmental stressors.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"310 ","pages":"Article 111928"},"PeriodicalIF":2.2,"publicationDate":"2025-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145058773","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":"Up-regulation of cell apoptosis, autophagy and mitochondrial dynamics in ovarian granulosa cells of Daurian ground squirrels during the pre-hibernation period","authors":"Xi Wang ,&nbsp;Hao Li ,&nbsp;Zhaomei Dong ,&nbsp;Wenjing Lu ,&nbsp;Jirui Chen ,&nbsp;Haolin Zhang ,&nbsp;Zhengrong Yuan ,&nbsp;Yuning Liu ,&nbsp;Qiang Weng ,&nbsp;Yingying Han","doi":"10.1016/j.cbpa.2025.111927","DOIUrl":"10.1016/j.cbpa.2025.111927","url":null,"abstract":"<div><div>Daurian ground squirrel (<em>Spermophilus dauricus</em>) exhibits both seasonal breeding and hibernation characteristics, but the adaptive changes in ovaries during the transition from seasonal reproduction to hibernation remain poorly understood. The aim of this study is to investigate the regulatory characteristics of granulosa cell apoptosis, autophagy and mitochondrial dynamics in the ovaries of wild Daurian ground squirrels across the April (breeding period), June (non-breeding period), and September (non-breeding and pre-hibernation period). The results proved that ovarian weight, as well as serum reproductive hormones, significantly decreased in June and September compared with April. Interestingly, unlike in June, many growing antral follicles emerged in the ovaries of wild Daurian ground squirrels during September. Furthermore, the molecular studies revealed a significant increase in ovarian gene expression related to cell apoptosis (<em>Casp3, Bax/Bcl-2</em>), autophagy (<em>Becn1, Pink1, Parkin, Sqstm1</em>) and mitochondrial dynamics (<em>Mfn1, Mfn2, Drp1</em>) during September compared to June. Additionally, immunohistochemical results indicated that the protein levels of the aforementioned genes and LC3A/B were concurrently upregulated, predominantly located in ovarian granulosa cells. Consistently, comparative analysis of ovarian transcriptomic data across different periods further confirmed that genes differentially expressed during the three periods were enriched in pathways related to apoptosis, autophagy, and mitochondrial dynamics. In summary, these results revealed a significant up-regulation of cell apoptosis, autophagy, and mitochondrial dynamism in ovarian granulosa cells of wild ground squirrels during the pre-hibernation period, may play a critical role in ovarian development for hibernation and subsequent stage.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"310 ","pages":"Article 111927"},"PeriodicalIF":2.2,"publicationDate":"2025-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145042473","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":"Optimising hatchery release strategies: Size-dependent training effects on the swimming performance of juvenile Schizothorax wangchiachii","authors":"Yuxin Fan ,&nbsp;Yan Lu ,&nbsp;Maohua Li ,&nbsp;Longjun Deng ,&nbsp;Xiaoshuai Liu ,&nbsp;Zhaobin Song","doi":"10.1016/j.cbpa.2025.111926","DOIUrl":"10.1016/j.cbpa.2025.111926","url":null,"abstract":"<div><div>The success of fish stock enhancement programmes is often limited by the high mortality of hatchery-reared individuals after their release. Poor swimming performance, a critical factor for survival, is a key reason for this low success rate. While exercise training can improve the physical fitness of fish, it is unclear whether these benefits are consistent across different sizes and developmental stages. Here, we aimed to determine how exercise training affects the aerobic and anaerobic swimming performance of the important economic fish, <em>Schizothorax wangchiachii</em>, across two different body size (age) classes. We subjected two sizes of hatchery-reared juvenile <em>S. wangchiachii</em> (4-month-old and 16-month-old) to 30 days of training. The fish underwent either high-speed aerobic training, low-speed aerobic training, anaerobic training, or were left untrained (control group). Following the training period, we measured their aerobic performance (critical swimming speed) and anaerobic performance (endurance time). We then compared these results with the performance of wild-caught juveniles of a similar age to the smaller cohort to gauge the effectiveness of the training. The training effects were strongly dependent on fish size. Aerobic exercise significantly improved the aerobic and anaerobic swimming performance of the smaller, 4-month-old juveniles. However, the training regimes had a much less pronounced effect on the larger, 16-month-old fish, with only their anaerobic performance showing some improvement. The low-speed aerobic training successfully raised the swimming capacity of the small hatchery-reared fish to a level that was not significantly different from their wild counterparts. Smaller juvenile <em>S. wangchiachii</em> benefit substantially more from aerobic exercise training than larger individuals. Therefore, considering both the training costs and the significant performance gains, implementing a low-speed aerobic exercise programme for smaller juveniles is the most effective and preferable strategy to prepare them for release, enhancing their potential for survival in the natural environment.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"309 ","pages":"Article 111926"},"PeriodicalIF":2.2,"publicationDate":"2025-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144926319","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 impact of short-term hyposalinity stress on the Pacific oyster (Magallana gigas) infested with boring sponges (Pione vastifica)","authors":"Ekaterina S. Kladchenko ,&nbsp;Olga L. Gostyukhina ,&nbsp;Daria S. Lavrichenko ,&nbsp;Viktoria A. Uppe ,&nbsp;Ekaterina A. Vodiasova ,&nbsp;Elina S. Chelebieva","doi":"10.1016/j.cbpa.2025.111925","DOIUrl":"10.1016/j.cbpa.2025.111925","url":null,"abstract":"<div><div>This study investigates the effects of 16-h short-term hyposalinity stress on the functional state of hemocytes in the Pacific oyster <em>Magallana gigas</em> (Thunberg, 1793) infected with the boring sponge <em>Pione vastifica</em> (Hancock, 1849). We also studied pro-oxidant-antioxidant status, expression of genes associated with oxidative stress and heat shock proteins, growth arrest and DNA damage in the <em>M. gigas</em> mantle. Our results showed a significant increase of intracellular reactive oxygen species levels in hemocytes under exposure of salinity 5 psu and 10 psu. A decrease in salinity from 18 psu to 10 psu led to a significant increase in superoxide dismutase activity in bivalves mantle. However, no alterations in mitochondrial membrane potential in hemocytes, catalase activity, thiobarbituric acid reactive substance levels, gene expression of antioxidant enzymes, and heat shock protein expression in the mantle under low salinity exposure were observed. The changes in the prooxidant-antioxidant balance during sponge infestation under low salinity conditions indicate the development of oxidative stress in this mollusk. Heat shock proteins, which can protect bivalves against osmotic stress, did not show higher expression under sponge infestation and hyposalinity stress conditions.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"309 ","pages":"Article 111925"},"PeriodicalIF":2.2,"publicationDate":"2025-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144889820","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":"Low temperature-driven physiological responses in ballan wrasse (Labrus bergylta): Stress, inflammation, and liver health","authors":"Peter Almaiz Palma ,&nbsp;Richard Broughton ,&nbsp;Elfred John C. Abacan ,&nbsp;Eduardo Jiménez-Fernández ,&nbsp;Alejandro P. Gutierrez ,&nbsp;Herve Migaud ,&nbsp;Mónica B. Betancor","doi":"10.1016/j.cbpa.2025.111923","DOIUrl":"10.1016/j.cbpa.2025.111923","url":null,"abstract":"<div><div>Abstract</div><div>This study investigated the impact of winter conditions on the physiology of ballan wrasse (<em>Labrus bergylta</em>), a widely used biological control agent in salmon farming. Fish were subjected to temperatures encompassing winter and summer conditions for short-term (8 days at 6, 10, or 14 °C) or long-term (2.5 months at 7 or 15 °C) period. Their stress, inflammatory, and hepatic responses were then examined. After short-term exposure, no significant differences were found in terms of morphology (bod weight, total length, condition factor), levels of stress markers (cortisol, glucose, and head kidney expression of stress-related genes), and inflammatory markers (circulating lipid inflammatory mediators, liver expression of <em>cox</em> and <em>lox</em> genes). However, at 6 °C, fish exhibited lower lactate levels and increased head kidney <em>cyp11a1</em> expression, indicating some metabolic and physiological changes during thermal acclimation. In comparison, long-term exposure to 7 °C resulted in stunted growth, along with elevated levels of stress markers, indicating tertiary stress response. Additionally, long-term exposure to 7 °C significantly lowered the levels of lipid anti-inflammatory mediators, particularly those synthesized by COX and derived from DHA and EPA, while increasing the pro-inflammatory cytokine <em>il-1β</em> expression in the head kidney, suggesting a heightened inflammatory capacity at low temperatures. Moreover, ballan wrasse at 7 °C displayed a larger hepatosomatic index and enlarged hepatocytes, indicative of energy substrate accumulation and storage in the liver. Findings highlight the physiological challenges and adaptive responses of ballan wrasse to winter temperatures, providing crucial insights for optimising farming practices and enhancing species' health, welfare and performance during deployment.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"309 ","pages":"Article 111923"},"PeriodicalIF":2.2,"publicationDate":"2025-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144867071","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":"Baseline peripheral serotonin levels in two sympatric Podarcis lizard species","authors":"Matea Brižić ,&nbsp;Romana Gračan ,&nbsp;Barbara Nikolić ,&nbsp;Sofia Ana Blažević","doi":"10.1016/j.cbpa.2025.111924","DOIUrl":"10.1016/j.cbpa.2025.111924","url":null,"abstract":"<div><div>Serotonin (5-hydroxytryptamine, 5HT) plays a crucial role in modulating physiological and behavioral traits in vertebrates, nonetheless little is known about its peripheral function in reptiles. Differences in central serotonin levels and behavior under serotonergic control have been observed in two sympatric lacertid lizard – <em>Podarcis siculus</em> and <em>P. melisellensis.</em> We compared baseline peripheral serotonin and tryptophan (Trp) levels, along with intestinal morphology, in these two species known to differ in behavior and invasiveness. Serum 5HT and Trp were measured using High-performance liquid chromatography (HPLC)-DAD, and intestinal enterochromaffin (EC) cell density and tissue morphology were assessed histologically (<em>N</em> = 82). <em>Podarcis melisellensis</em> exhibited significantly higher serum 5HT concentrations, particularly in males, with no corresponding differences in Trp levels or EC cell density. Histological analysis showed preserved intestinal architecture and similar structures in all examined individuals. Histomorphometric analysis revealed sex- and species-specific variation in intestinal structure, independent of sampling location. These findings suggest that interspecies differences in peripheral serotonin homeostasis may arise from physiological mechanisms beyond EC cell abundance, possibly involving altered precursor availability, synthesis, or degradation. Our results highlight peripheral serotonin as a potential physiological marker underlying behavioral and ecological divergence between closely related lizard species.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"309 ","pages":"Article 111924"},"PeriodicalIF":2.2,"publicationDate":"2025-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144979322","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}