National Demonstration Center for Experimental Fisheries Science Education, Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture, Engineering Research Center of Aquaculture, Shanghai Ocean University, Shanghai, China.
National Demonstration Center for Experimental Fisheries Science Education, Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture, Engineering Research Center of Aquaculture, Shanghai Ocean University, Shanghai, China.
Comp Biochem Physiol C Toxicol Pharmacol. 2021 Dec;250:109127. doi: 10.1016/j.cbpc.2021.109127. Epub 2021 Jul 9.
Ammonia nitrogen pollution seriously affects the economic benefits of Chinese mitten crab (Eriocheir sinensis) farming. In this study, we first evaluated the protective effects of melatonin (MT) on immune parameters, antioxidant capacity, and digestive enzymes of E. sinensis under acute ammonia nitrogen stress. The results showed that ammonia-N stress significantly decreased the antibacterial ability of crabs, nevertheless MT could significantly improve it under ammonia-N stress (P < 0.05). Ammonia-N group hemolymph antioxidant capacity indicators (T-AOC, T-SOD, GSH-Px) were significantly decreased than control (p < 0.05), while the MT ammonia-N group hemolymph T-SOD activity significantly increased than ammonia-N group (p < 0.05). For hepatopancreas, ammonia-N group GSH-PX activity significantly decreased than control group, but MT ammonia-N group was significant increased than ammonia-N (p < 0.05). Ammonia-N stress has significantly increased the content of MDA in hemolymph and hepatopancreas (p < 0.05), but MT ammonia-N treatment significantly decreased than ammonia-N group (p < 0.05). Compared with the control group, ammonia-N significantly reduced the activities of Trypsin in the intestine and hepatopancreas (p < 0.05), while MT ammonia-N group can significantly improve the intestinal trypsin activity than ammonia-N (p < 0.05). The intestinal microbiota of E. sinensis results showed that ammonia-N stress significantly decreased the relative abundance of Bacteroidetes (p < 0.05). Ammonia-N stress significantly decreased the Dysgonomonas and Rubellimicrobium, and the Citrobacter significantly increased. In summary, melatonin has a protective effect on E. sinensis under ammonia-N stress. Acute ammonia-N stress may lead to the decrease of probiotics and the increase of pathogenic bacteria, which may be closely related to the impairment of digestive function and immune function.
氨氮污染严重影响中华绒螯蟹（Eriocheir sinensis）养殖的经济效益。本研究首先评估了褪黑素（MT）对中华绒螯蟹在急性氨氮胁迫下免疫参数、抗氧化能力和消化酶的保护作用。结果表明，氨氮胁迫显著降低了蟹的抗菌能力，但 MT 能显著改善氨氮胁迫下的抗菌能力（P < 0.05）。氨氮组血淋巴抗氧化能力指标（T-AOC、T-SOD、GSH-Px）均显著低于对照组（p < 0.05），而 MT 氨氮组血淋巴 T-SOD 活性显著高于氨氮组（p < 0.05）。对肝胰腺而言，氨氮组 GSH-PX 活性显著低于对照组，但 MT 氨氮组显著高于氨氮组（p < 0.05）。氨氮胁迫显著增加了血淋巴和肝胰腺中 MDA 的含量（p < 0.05），但 MT 氨氮处理显著低于氨氮组（p < 0.05）。与对照组相比，氨氮显著降低了肠和肝胰腺中胰蛋白酶的活性（p < 0.05），而 MT 氨氮组能显著提高肠胰蛋白酶的活性（p < 0.05）。中华绒螯蟹肠道微生物组结果表明，氨氮胁迫显著降低了拟杆菌门（Bacteroidetes）的相对丰度（p < 0.05）。氨氮胁迫显著降低了 Dysgonomonas 和 Rubellimicrobium 的丰度，而 Citrobacter 的丰度显著增加。综上所述，褪黑素对中华绒螯蟹在氨氮胁迫下具有保护作用。急性氨氮胁迫可能导致益生菌减少和致病菌增加，这可能与消化功能和免疫功能受损密切相关。
