Abstract：
The swimming activity, although an essential trait in the life cycle of fish, is still poorly understood in farmed fish. The current study aimed to investigate the impact of short-term induced swimming on the immune and antioxidant defence systems in European eel (Anguilla anguilla). Sixteen male yellow European eels (total length: 39.9 ± 0.7 cm; body weight: 108.8 ± 6.1 g) were individually placed in swimming flumes and divided into two groups: i) no swimming (n = 8); and ii) induced-swimming (n = 8) at 0.3 body lengths (BL)·s-1 for 7 h. Swimming resulted in a 2-fold lower cortisol concentration in plasma, whereas plasma glucose, lactate, and several immune-related parameters did not present variations between groups. Interestingly, swimming led to higher lysozyme, peroxidase, and protease activities in skin mucus, whereas bactericidal activity did not show differences among groups. Additionally, the gene expression of interleukin 1 beta showed an up-regulation in the skin of fish with induced swimming, while no differences were observed in the head-kidney or gills. Furthermore, modulation of the antioxidant status was observed in the liver and posterior skeletal muscle after induced swimming. Fish subjected to swimming showed lower lipid peroxidation and higher reduced glutathione levels, increasing the reduced/oxidized glutathione ratio. However, no variations in the antioxidant status were observed between groups in the anterior skeletal muscle. This study showed modulation of immune and oxidative stress markers in European eels upon short-term induced swimming compared to non-swimming fish.
摘要：
游泳活动,虽然是鱼类生命周期中的一个重要特征，在养殖鱼类中仍然知之甚少。本研究旨在研究短期诱导游泳对欧洲鳗鱼（安圭拉anguilla）免疫和抗氧化防御系统的影响。将16只雄性黄色欧洲鳗鱼（总长度：39.9±0.7厘米；体重：108.8±6.1克）分别放在游泳水槽中，并分为两组：i）不游泳（n=8）；ii）以0.3体长（BL）·s-1诱导游泳（n=8）7小时。游泳导致血浆中皮质醇浓度降低2倍，而血浆葡萄糖，乳酸，一些免疫相关参数在组间没有差异。有趣的是,游泳导致更高的溶菌酶，过氧化物酶,和皮肤粘液中的蛋白酶活性，而杀菌活性在组间没有差异。此外,白细胞介素1β的基因表达在诱导游泳的鱼皮中表现出上调，而在头肾或g中没有观察到差异。此外，诱导游泳后，在肝脏和后骨骼肌中观察到抗氧化状态的调节。游泳的鱼显示出较低的脂质过氧化和较高的还原型谷胱甘肽水平，增加还原/氧化谷胱甘肽的比例。然而,在前骨骼肌中,两组间的抗氧化状态没有变化.这项研究表明，与非游泳鱼相比，短期诱导游泳后欧洲鳗鱼的免疫和氧化应激标志物的调节。
