海人酸致痫动物模型脑内一氧化氮,一氧化氮合酶的变化

目的探讨一氧化氮（ＮＯ）、一氧化氮合酶（ＮＯＳ）在癫痫发生中的作用及ＮＯＳ抑制剂的作用。方法采用海人酸致痫大鼠模型并应用ＮＯＳ抑制剂Ｌ－硝基精氨酸甲酯（Ｌ－ＮＡＭＥ），分别在致痫后３０分钟、６０分钟取海马组织，匀浆后测定ＮＯ及ＮＯＳ水平。结果致痫３０分钟后海马ＮＯ含量显著升高，至６０分钟恢复正常；ＮＯＳ活性水平增高＞５０％；Ｌ－ＮＡＭＥ明显抑制大鼠的痫性发作，应用ＮＯＳ抑制剂组大鼠海马ＮＯ、ＮＯＳ含量明显下降。结论癫痫发作后脑内ＮＯ、ＮＯＳ活性增强，ＮＯＳ抑制剂通过抑制酶活性使ＮＯ生成降低，并完全抑制痫性发作。ＮＯＳ活性受抑制＞４８％即可产生明显效果。提示ＮＯ可能有内源性致痫作用。

The change of nitric oxide and nitric oxide synthase in the hippocampus of KA treated rats

Objective To study the role of nitric oxide(NO), nitric oxide synthase (NOS) and the inhibitor of NOS in the epilepsy. Methods The Wistar rats of epilepsy were induced by kainic acid(KA), and some of them were pretreated with NOS inhibitorL nitro arginine methyl ester(L NAME), the levels of NO and NOS in the hippocampus were measured in 30,60 min respectively after epilepsy. Results The concentrations of NO were significently increased in 30 min,but returned to the normal level in 60 min. The activity of NOS was elevated more than 50%.L NAME dramatically inhibited the seizures and the concentrations of NO and NOS in the hippocampus decreased with inhibitor of NOS. Conclusion The activities of NO and NOS were increased after seizures, NOS made the decrease of NO by inhibitive enzyme activity,and inhibited the seizures.The inhibitor of NOS could control the seizures when the activity of NOS was inhibited above 48%. It suggested that NO might have the endogenous convulsant effect.