氨氮对中华鳑鲏的急性毒性及2种代谢酶活性的影响

摘要

The acute toxicity of ammonia nitrogen to Rhodeus sinensis was performed and the activities of two metabolism enzymes (catalase-CAT & alkaline phosphatase-AKP) were determined under its stress with static method simulating the ammonia nitrogen stress in natural waters.The results showed as follows: The 24 LC50 of ammonia nitrogen was 263.28 mg/L at pH 7.4 and 25 ℃, which was higher than that of Brachydanio rerio and Siniperca chuatsi.The experiment of am-monia exposure indicated that their activities were significantly affected by the stress from ammonia nitrogen including con-centration and exposure time, even interaction.It is concluded that R.sinensis can tolerate high concentrations of ammonia nitrogen for a short period compared with most other fishes; however, its immune systems were impaired with the extension time.%采用静水法模拟养殖水体中氨氮胁迫,研究氨氮对中华鳑鲏(Rhodeus sinensis)的急性毒性效应;测定血清中2种代谢酶类(过氧化氢酶和碱性磷酸酶)的酶活性.结果表明在水温25 ℃, pH 7.4时,氨氮24 h 的半致死浓度(LC50)为263.28 mg/L,高于斑马鱼(Barchydanio rerio var)、鳜(Siniperca chuatsi);氨氮暴露试验表明氨氮浓度和暴露时间均会对2种酶活性造成显著影响,并且两者之间存在交互作用;中华鳑鲏在短时间内对高浓度氨氮刺激具有一定的耐受性,但随着暴露时间延长,氨氮对机体的免疫系统会产生抑制作用.