溴氰菊酯对大鼠中枢神经系统一氧化氮合成酶活性的影响

本研究在发现溴氰菊酯（ＤＭ）可使突触前膜谷氨酸释放增加的基础上，探讨了ＤＭ对大鼠中枢神经系统不同部位的一氧化氮合成酶（ＮＯＳ）活性的影响。利用不同性质阻断剂，对影响ＮＯＳ活性的可能机理进行了研究。结果发现，ＤＭ可引起大脑皮层、海马及小脑部位的ＮＯＳ活性显著增加。Ｌ－硝基精氨酸是ＮＯＳ的竞争性抑制剂，它可抑制由ＤＭ所致ＮＯＳ活性的升高。尼莫地平是一种电压依赖性钙通道阻断剂，它也可以有效的抑制ＤＭ所致ＮＯＳ活性的增加。认为ＤＭ导致神经毒性的机理可能是通过谷氨酸过量释放，诱导ＮＯＳ活性的升高，造成神经元的损伤。

Effect of deltamethrin on the activity of nitric oxide synthase in the central nervous system of rat

On the basis of previous observation that deltamethrin(DM) can increase release of glutamate from presynaptic membrane,the present study was undertaken to investigate the influence of DM on the activity of nitric oxide synthase(NOS) from different parts of central nervous system of rat.The possible mechanism of DM effecting the NOS activity was explored by using two blockers of different properties. The result showed that DM can enhance significantly the avtivity of NOS from cerebral cortex,hippocampus,and cerebellum,respectively. N nitro L arginine,a competitive inhibitor of NOS,can limited the enhancement of NOS activity caused by DM.Nimodipine,a voltage dependent Ca 2 channel blocker,can also made an inhibition of NOS activity incresing by DM.This observation suggested that neurotoxicity mechanism of DM may be injury of neuron elicited by the enhancement of NOS activity resulted from overrelease of glutamate.