College of Biological and Environmental Sciences, Zhejiang Wanli University, Ningbo 315100, China.
College of Biological and Environmental Sciences, Zhejiang Wanli University, Ningbo 315100, China.
Fish Shellfish Immunol. 2024 Nov;154:109936. doi: 10.1016/j.fsi.2024.109936. Epub 2024 Sep 30.
Transport stress always poses a threat to aquatic animals. Transportation under low temperatures was often used to relieve transport stress in practical production of Chinese soft-shelled turtle Pelodiscus sinensis, but their effect on the turtle's intestinal barrier remains unclear. In this study, P. sinensis (initial weight 200 ± 20 g) were exposed to simulated transport stress for 12 h at control (30 °C) and low (20 °C) temperature, and then recovery for 24 h, and each treatment had 4 replicates with each replicate containing 4 turtles. The results showed that transportation induced obvious morphological and histological damages in intestinal villus, with a down-regulated expression of the tight junction related genes. Besides turtles in transport group showed an oxidative stress in intestine, which stimulated a physiological detoxification response together with apoptosis. Low temperature transport plays a mitigative effect on the transport stress of turtle intestine via relieved stress response. Specifically, the intestinal villus/crypt (V/C) ratio and the expression of tight junction genes in the low-temperature group were significantly higher compared to the control temperature group, while stress response parameters such as intestinal cortisol levels and hsp expression were significantly lower in the low-temperature group. Additionally, low temperature alleviated oxidative damage and apoptosis caused by transport stress relative to the control temperature group. However, the protective effect of low temperature on P. sinensis intestine was limited, especially after the temperature recovery stage. Overall, the findings of the present study demonstrated that transport stress would induce the disruption of intestinal integrity and oxidative damage, also activated the mucosal immunity and antioxidant enzyme system response of turtles. It was also suggested that low temperature could alleviate the adverse effects of transport stress on intestinal integrity through modulation of oxidative status and apoptosis, whereas much less impact after temperature recovery.
运输应激总是对水生动物构成威胁。在中华鳖 Pelodiscus sinensis 的实际生产中，常采用低温运输来缓解运输应激，但低温运输对鳖肠道屏障的影响尚不清楚。本研究中，中华鳖（初始体重 200±20g）在对照（30°C）和低温（20°C）下分别经受 12 小时模拟运输应激，然后恢复 24 小时，每个处理有 4 个重复，每个重复包含 4 只鳖。结果表明，运输导致肠道绒毛明显的形态和组织学损伤，紧密连接相关基因表达下调。此外，运输组鳖的肠道出现氧化应激，刺激了生理解毒反应和细胞凋亡。低温运输通过缓解应激反应对鳖肠的运输应激起到缓解作用。具体而言，低温组的肠道绒毛/隐窝（V/C）比和紧密连接基因的表达明显高于对照组，而低温组的肠道皮质醇水平和 hsp 表达等应激反应参数明显低于对照组。此外，低温缓解了运输应激引起的氧化损伤和凋亡。然而，低温对中华鳖肠道的保护作用是有限的，特别是在温度恢复阶段。综上所述，本研究结果表明，运输应激会导致肠道完整性破坏和氧化损伤，同时激活鳖的黏膜免疫和抗氧化酶系统反应。研究还表明，低温可以通过调节氧化状态和凋亡来缓解运输应激对肠道完整性的不利影响，但在温度恢复后影响较小。
