氨氮胁迫对翘嘴鳜幼鱼抗氧化酶、消化酶活性及应激相关基因表达的影响OA

In order to understand the response mechanism of antioxidant system and digestion system of mandarin fish(Siniperca chuatsi)under ammonia nitrogen stress,the activities of related enzymes[glutathione(GSH),superoxide dismutase(SOD),catalase(CAT),lipid peroxide(LPO),pepsin,gastric amylase(AMS),gastric lipase(LPS)]and the expression of stress-related genes(IL-1β,IL-8,TNF-α,HSP90α)in the liver and stomach of juvenile S.chuatsi with body weight of(15.27±0.67)g under six ammonia nitrogen stress concentrations(0,10,20,30,40,50 mg/L)were studied.The results showed that the activities of SOD,CAT and GSH in the liver increased at first and then decreased,while LPO activities increased gradually under 96 h of ammonia nitrogen stress.The gene express of IL-1β and HSP90α showed a decreasing trend after increasing,while TNF-α express increased gradually,and IL-8 express showed the trend of decreasing,increasing and decreasing.The activities of pepsin increased first and then decreased,while AMS and LPS activities increased gradually.Studies have shown that fish can respond to oxidative stress damage by increasing the activities of antioxidant enzymes and up-regulation of stress-related gene expression,and at the same time induce the increase of digestive enzyme activities in the stomach to provide energy for the body under the stress of low concentration of ammonia nitrogen.However,the activities of antioxidant enzymes and the expression of HSP90α gene were inhibited by high concentration ammonia nitrogen stress.