目的　探讨脑缺血时微血管管径与一氧化氮释放的相关性。方法　采用激光多谱勒和电化学方法 ,测量沙土鼠软脑膜微血管管径和NO的变化。结果　脑缺血时 ,软脑膜细动脉立即收缩成线状 ,5min后开始舒张 ,缺血 4 0± 10min时 ,软脑膜细动脉扩张至最大值 ,而后缓慢收缩 ;细动脉内的NO于缺血始合成增加 ,呈周期间断性释放 ,周期间隔为 5～ 8min ,持续时间 3～ 5min ,缺血 10～ 4 0min ,NO增至最大值 ,而后逐渐减少 ,二者变化具有正相关性。结论　脑缺血时NO分泌调控脑微血管舒缩功能 Objective To investigate the correlation between the microvascular diameter and the release of nitric oxide during cerebral ischemia. Methods The changes of microvessel diameter and NO in gerbils were measured by laser Doppler and electrochemical methods. Results Cerebral ischemia, the leptomeningeal artery immediately contracted into a linear pattern and began to relax 5 min later. When the ischemia was 40 ± 10 min, the leptomeningeal artery dilated to its maximum and then contracted slowly; The initial synthesis increased intermittently, and the cycle interval was 5 ~ 8min, duration 3 ~ 5min, ischemia 10 ~ 4 0min, NO increased to the maximum, and then decreased gradually, the two had a positive correlation. Conclusion NO secretion during cerebral ischemia regulates cerebral vasomotor function