毒死蜱与鱼肝微粒体P450的相互作用

为了评估毒死蜱对水生生态系统的风险,比较研究了毒死蜱对斑马鱼、麦穗鱼及太阳鱼的急性毒性,3种鱼肝微粒体P450酶系对毒死蜱的脱硫转化作用及毒死蜱对肝微粒体P450酶系的影响。结果表明,毒死蜱对斑马鱼、麦穗鱼及太阳鱼的96 h-LC50分别为1.94, 0.0273,0.0681 mg·L-1。3种鱼肝微粒体P450酶系对毒死蜱代谢的Vmax/Km值分别为：1.67×10⁴,5.00×10⁴,2.00×10⁴,即代谢能力大小为麦穗鱼＞太阳鱼＞斑马鱼,与急性毒性试验结果相吻合,从而P450酶系的脱硫转化活性可以一定程度上解释毒死蜱对3种鱼的毒性差异。试验浓度毒死蜱对3种鱼的P450酶系的影响不显著。

Interaction between chlorpyrifos and hepatic microsomal cytochrome P450 enzyme system in fish

Acute toxicity of chlorpyrifos to Danio rerio, Pseudorasbora parva, and Lepomis gibbosus, oxidative activation of chlorpyrifos catalyzed by hepatic microsomal cytochrome P450 system, and influence of chlorpyrifos to the P450 system were studied to evaluate the risk of chlorpyrifos on ecology system. 96 h LC50 of chlorpyrifos to the Danio rerio, the Pseudorasbora parva, and the Lepomis gibbosus was measured to be 1.94, 0.0273, 0.0681 mg·L-1, respectively. The Vmax/Km of chlorpyrifos oxidation catalyzed by P450 system was measured to be 1.67×10⁴,5.00×10⁴,2.00×10⁴,respectively, indicating that the oxidative metabolism capacity of the P450 system was the highest in Pseudorasbora parva and the lowest in Danio rerio, which matched the results of acute toxicity tests. The influence of chlorpyrifos to the P450 system was not obvious．