摘要 目的：研究一氧化氮合成酶抑制剂(L-NNA)对大鼠半球持续缺血时纹体多巴胺(DA)释放的影响。方法：阻断大鼠基底动脉和双侧颈总动脉作为半球缺血模型，用微透析法结合高压液相法测定半球缺血30，60，90，120分钟时大鼠纹体DA的释放。结果：大鼠半球缺血30分钟时，纹体DA的释放形成高峰，其后逐渐下降，但都高于缺血前释放量。L-NNA能明显抑制缺血时纹体DA的不正常释放。结论：NO参与了缺血时纹体DA释放的调节。L-NNA抑制半球缺血时DA的不正常释放可能是其保护缺血大脑的机制之一。

Abstract Objective: To study the influence of NOS inhibitor L-NNA on therelease of dopamine from rat striatums during persistent global ischemia. Methods:Thebilateral carotid arteries and basilar arteries of rats were occluded as the model ofglobal ischemia. The releases of DA were determined by microdialysis and HPLC methods.Results:The peak of DA release from rat striatum was formed during 30 min globalischemia,then,it was decreased gradually. However,all of the DA releases during60,90,120min global ischemia were significantly higher than that before ischemia. Theabnormal release of DA from ischemic striatums were significantly inhibited by L-NNA.Conclusion:NO is involved in the regulation of DA release from striatum during cerebral ischemia. The abnormal DA release inhibited by L-NNA during global ischemia may be one ofthe protective mechanism of this agent on brain ischemia.

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