氯菊酯和氯氰菊酯对大鼠脑突触体Ca^(2+)-和Ca^(2+),Mg^(2+)-ATP酶活性的抑制

Inhibitory effects of pcrmethrin and cypermethrin on Ca^(2+)- and Ca^(2+),Mg^(2+)-ATPase activities of rat brain synaptosomes

氯菊酯可明显抑制Ca^(2+)—ATP酶活性,其抑制作用是可逆的,底物动力学分析表明为非竞争性抑制,介质的酸度可影响其抑制效应;氯氰菊酯对该酶活性无明显影响.氯菊酯和氯氰菊酯均能可逆性地抑制Ca^(2+),Mg^(2+)—ATP酶活性,但氯菊酯为反竞争性抑制.且有一定的pH依赖性,而氯氰菊酯为非竞争性抑制,其抑制率基本不受pH的影响,表明这两种杀虫剂在Ca^(2+) ,Mg^(2+)—ATP酶上有不同的结合位点.

The inhibitory effects of permethrin and cypermethrin on Ca2+-and Ca2+,Mg2+-ATPase activities of rat brain synaptosomes were investigated.Permethrin caused a significant decrease in Ca2+-ATPase activity,while cypermethrin showed no such effect.The inhibition on Ca2+-ATPase by permethrin was reversible and non-competitive because altered Vmax value showed no significant change in Km value with respect to the activation by ATP.The effectiveness was pH dependent.Both permethrin and cypermethrin reversibly inhibited Ca2+,Mg2+-ATPase activity.According to altered Vmax and Km values permethrin showed anuncompetitive inhibition,which had certain pH dependence while cypermethrin a noncompetitive inhibition which was pH independent,and this was indicated by the same alteration of kinetic parameters as inhibition on Ca2+-ATPase by permethrin.The possible relation between inhibited Ca2+-and Ca2+,Mg2+-ATPase activities and the neurotoxicity of pyrethroids was discussed.