氨氮对中华鳑鲏的急性毒性及2种代谢酶活性的影响

Acutetoxicity of ammonia nitrogen to Rhodeus sinensis and its effects on two metabolism enzymes

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(LC_(50))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。

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 ammonia exposure indicated that their activities were significantly affected by the stress from ammonia nitrogen including concentration 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.