海鱼AChE监测海水有机磷农药的可行性研究

A STUDY ON THE FEASIBILITY OF MORNITORING ORGANOPHOSPHORUS PESTICIDES IN SEAWATER USING AChE IN MARINE FISH:Lateolabrax japonicus (cuvier)

有机磷农药 (OPs)对乙酰胆碱酯酶 (AChEEC 3.1 .1 .7)具有专一性抑制作用 ,因此AChE常作为淡水和土壤OPs污染的特异性标识物 (biomarker)。本文在海水背景下 ,通过测定两种有机磷农药 (马拉硫磷和甲基对硫磷 )对海洋鱼类—鲈鱼 [Lateolabraxjaponicus(cuvier) ]脑组织AChE的抑制效应 ,分析了海鱼AChE监测海水OPs的可行性。结果显示 ,抑制时间为 2 0min时 ,抑制程度达到相对稳定 ;在低浓度OPs抑制下 ,纯酶液比粗酶液表现出更好的敏感性 ,对马拉硫磷和甲基对硫磷的灵敏度分别达到 0 .2 8μg·L 1和 0 .2 μg·L 1;在一定浓度范围内 ,AChE活力对OPs具有显著的线性响应。研究表明 ,利用鲈鱼AChE指示和监测海水OPs的微污染是完全可行的。

Organophosphorus pesticides(OPs) are a specific inhibitor of acetylcholinesterase (AChE EC 3.1.1.7).AChE has therefore been regarded as a specific biomarker of the exposure to and effect of OPs. An in vitro method for detecting two OPs: malathion and methyl parathion in seawater using the brain AChE from a marine fish \[ Lateolabrax japonicus (cuvier)\] is proposed. The optimum incubation time and the effect of different purification of AChE on the inhibition of OPs are reported. It is found that the purified AChE is more sensitive to the two OPs than the crude AChE. The detection limits for malathion and methyl parathion are found to be 0.28 g L 1 and 0.20g L 1 respectively. Moreover, there is a good linearity between the percent inhibition of AChE activity and the concentration of OPs. Therefore, it is feasible to indicate and detect OPs pollution in seawater with this AChE.