Browsing by Subject "Lactate"

Now showing 1 - 4 of 4
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    Open Access
    Daily rhythms of acute stress responses and antioxidant systems in the European sea bass (Dicentrarchus labrax): effects of the time of the year
    (Elsevier, 2024-04-15) Samorì, Elisa; Rodríguez, Inmaculada; Paullada Salmerón, José Antonio; Sánchez Alacid, Laura; Muñoz Cueto, José Antonio; Sánchez Vázquez, Francisco Javier; López Olmeda, José Fernando; Fisiología
    Fish reared in aquaculture face various acute stressors, including air exposure during handling. Research on the stress response in fish can provide essential insights into their physiology and help define better aquaculture practices. In this study, we investigated the daily rhythms in the stress-axis response of the European sea bass (Dicentrarchus labrax) subjected to an acute stressor consisting of air exposure (1 min), and how this response is influenced by the time of the day and the season of the year. In addition, rhythms in antioxidant systems were also assessed. The experiments were performed in late Autumn (December) and late Spring (June), with natural photoperiod (10 L:14D and 15 L:9D, respectively) and water temperature (ranging from 19.47 ± 0.17 °C in December to 22.13 ± 0.13 °C in June). Samples were collected throughout a 24-h cycle at Zeitgeber time (ZT) 0.5, 4, 7.5, 12, 16, 20, and 24.5 h at both seasons. At each sampling point, an untreated control (CTRL) group was sampled, while a STRESS group was exposed to air for one minute, returned to the tank, and sampled one hour later. Fish were sacrificed to collect plasma samples, hypothalamus and liver. Plasma samples were analyzed for cortisol, glucose, and lactate. In the hypothalamus, the mRNA expression levels of corticotropin-releasing hormone (crh) and crh-binding protein (crh-bp) were quantified using quantitative RT-PCR (qPCR). In the liver, genes related to antioxidant systems (catalase, superoxide dismutase 1, glutathione peroxidase,and glutathione reductase) and mitochondrial markers of stress (uncoupling protein 1, cytochrome c oxidase IV and peroxiredoxin3) were also analyzed by qPCR. The results revealed that most stress indicators (cortisol, cat, sod1, gsh-px, gsr, ucp1, coxIV) displayed daily rhythms. Furthermore, the stress response was significantly influenced by the time of day and the season in which the stressor was applied. In June, cortisol and glucose responses to stress were higher during the day than at night. The increase observed after stress in genes related to the antioxidant system was more significant in June than in December. Conversely, the response of mitochondrial markers was greater in December. Taken together, these findings highlight that the stress response of the European sea bass is time-dependent, both on a daily and a seasonal basis. This emphasizes the importance of considering cyclic environmental factors and circadian rhythms in aquaculture procedures to enhance fish welfare.
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    Open Access
    The effects of environmental enrichment on the physiology, behaviour, productivity and meat quality of pigs raised in a hot climate
    (MDPI, 2019-05-13) Fàbrega, Emma; Marcet-Rius, Míriam; Vidal, Roger; Escribano Tortosa, Damián; Cerón Madrigal, José Joaquín; Manteca, Xavier; Velarde, Antonio; Producción Animal
    Some positive effects regarding the use of enrichment material on the stimulation of pig exploration and a reduction in redirected behaviour was reported. This study aims to evaluate the effects of four enrichment materials on the behaviour, physiology/health, performance and carcass and meat quality in pigs kept in Spanish production conditions. Ninety-six male pigs (six pigs/pen) ranging from 70 to 170 days old were used. Chains were used for the control group (CH), and wooden logs (W), straw in a rack (S) or paper (P) were also used. The pigs were subjected to two pre-slaughter treatments: 0 or 12 h of fasting. Their behaviour was observed for 12 weeks using scan and focal sampling. Samples of the Neutrophil: Lymphocyte (N:L) ratio and lactate were obtained from the pigs at 66 and 170 days old. Saliva samples for Chromogranin-A (CgA) were obtained at 67, 128, 164 and 170 days old. The weight, skin lesions and feed intake of the pigs were recorded. S triggered more exploratory behaviour than W and CH (P < 0.001). Skin lesions and redirected behaviour were lower for pigs with S (P < 0.01 and P < 0.05, respectively). The pigs offered S presented lower CgA after no fasting than pigs with P or CH (P = 0.055). Lactate was higher in pigs with W and CH treatments, regardless of fasting (P < 0.05). The N:L ratio increased over time (P < 0.05). No other significant effects were found. Overall, straw in a rack was the enrichment material that enhanced pig inherent behaviour.
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    Open Access
    The influence of sex on high intensity swimming test
    (Servicio de Publicaciones. Universidad de Murcia, 2025) López-León, Inmaculada; Leitão, Luís; Fernandes da Silva, Sandro; Sánchez-Oliver, Antonio Jesús; Domínguez, Raúl; Lara, Javier Moreno; Sin departamento asociado
    Differences based on sex have been reported in the energetic and mechanical demands of different exercise modalities; however, no studies have analyzed the influence of sex during high-intensity swimming. The aim of this study was to determine sex-based differences in the response to a high intensity swimming test on performance, fatigue, blood lactate concentrations (BLa) and rating of perceived exertion (RPE). A total of 23 competitive swimmers (11 males; 12 females) performed 8 sets of 50-m at maximum intensity with 2 minutes of recovery intra-sets. Pre- and post-exercise, BLa was analysed. In addition, RPE were administered at the end of each 50-m. Differences were detected in the high intensity swimming test on sex (η²p=0.566; p<0.001) and time (η²p=0.233; p<0.001), but not for the interaction time·sex (p>0.05). It was reported an effect for time on BLa (η²p=0.947; p<0.001) and RPE (η²p=0.559; p<0.001), but not for sex nor the interaction time·sex (p>0.05). Although males are faster, not differences were found in BLa, fatigue nor RPE between sexes. These results could be mediated by the all-out nature of the protocol and practical implications suggest that it is not necessary to adapt the training load in high intensity swimming session attending to the sex of the athletes.
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    Open Access
    Upregulation of autophagy and glycolysis markers in keloid hypoxic-zone fibroblasts: Morphological characteristics and implications
    (Universidad de Murcia. Departamento de Biología Celular e Histología, 2018) Okuno, Ryoko; Ito, Yuko; Eid, Nabil; Otsuki, Yoshinori; Kondo, Yoichi; Ueda, Koichi
    Keloid is a fibro-proliferative skin disorder with tumor-like behavior and dependence on anaerobic glycolysis (the Warburg effect), but its exact pathogenesis is unknown. Although autophagy is widely accepted as a lysosomal pathway for cell survival and cellular homeostasis (specifically upon exposure to stressors such as hypoxia), very few studies have investigated the involvement of autophagy and related glycolytic effectors in keloidogenesis. Here the authors examined the expression and cellular localization of autophagy proteins (LC3, pan-cathepsin), glycolytic markers (LDH, MCT1, MCT4) and the transcription factor HIF isoforms in human keloid samples using immunohistochemical analysis and double-labeling immunofluorescence methods. Based on H&E staining and expression of CD31, keloids were compartmentalized into hypoxic central and normoxic marginal zones. Vimentin-expressing fibroblasts in the central zone exhibited greater autophagy than their marginalzone counterparts, as evidenced by increased LC3 puncta formation and co-localization with lysosomal pan-cathepsin. LDH (a lactate stimulator), MCT4 (a lactate exporter) and HIF-1α expression levels were also higher in central-zone fibroblasts. Conversely, HIF-2α expression was upregulated in fibroblasts and endothelial cells of the peripheral zone, while MCT1 was expressed in both zones. Taken together, these observations suggest that upregulation of autophagy and glycolysis markers in keloid hypoxic-zone fibroblasts may indicate a prosurvival mechanism allowing the extrusion of lactate to marginal-zone fibroblasts via metabolic coupling. The authors believe this is the first report on differential expression of autophagic and glycolytic markers in keloid-zone fibroblasts. The study results indicate that autophagy inhibitors and MCT4 blockers may have therapeutic implications in keloid treatment