食蚊鱼Gambusia affinis脑乙酰胆碱酯对杀螟松的反应及恢复(英文)

BRAIN ACETYLCHOLINESTERASE RESPONSE AND RECOVERY IN MOSQUITOFISH (-GAMBUSIA AFFINIS-) EXPOSED TO FENITROTHION

在静水系统中用不同浓度的杀螟松处理食蚊鱼 96 h分别于第 2 4、4 8和 96 h测定脑乙酰胆碱酯酶(ACh E)的活性。另一些鱼在接触杀螟松之前分别用胡椒基丁醚 (PBO)和磷酚三苯酯 (TPP)做预处理。结果表明 ,在 0 .4 mg/ L和 1.3mg/ L的亚致死浓度下 ,杀螟松对 ACh E活性的抑制率分别为 4 4 .2 %和 6 5.7%与用杀螟松单独处理的鱼相比 ,TPP预处理的鱼 ACh E活性更低 ,而 PBO处理后的鱼 ACh E活性较高。本项研究还测定了鱼经过 96 h杀螟松处理再移到清水中之后 ACh E的恢复情况。经过 8d的恢复期 ,用杀螟松单独处理和经 TPP处理的鱼 ,其 ACh E仍低于对照。

Mosquitofish (-Gambusia affinis-) were exposed to different concentrations of fenitrothion in a static system for 96h. Brain acetylcholinesterase (AChE) activity was evaluated after 24, 48 and 96h insecticide exposure. Fish were also pretreated with piperonyl butoxide (PBO) or triphenyl phosphate (TPP) and then exposed to fenitrothion. Results indicated that fenitrothion produced significant inhibitory effect on AChE ranging from 44.2% to 65.7% at the sublethal concentrations 0.4 mg/L and 1.3mg/L, respectively. Fish pretreated with TPP exhibited decreased AChE activity whilst in PBO pretreated group increased activity was observed compared with those exposed to fenitrothion alone. The pattern of AChE recovery was also assessed in fish previously exposed for 96h and then transferred to clean (chemical free) water. Following 8 days of recovery period, the AChE activity of those exposed to fenitrothion alone and pretreated with TPP was still lower than that of the control.