大鼠脑缺血模型血脑屏障结构和功能状态的研究

目的 探讨脑缺血再灌注后血脑屏障结构和功能改变的规律性,为相关血管源性脑水肿的防治提供形态学和功能学基础.方法 采用改良的Longa线拴法,制备大脑中动脉闭塞局灶性脑缺血不同时程再灌注模型,硝酸镧心脏灌注,额顶叶取材,电镜下观察血脑屏障超微结构的变化;伊文思蓝颈总动脉注射,脑组织匀浆制备,分光光度仪伊文思蓝通透性定量分析,评价血脑屏障功能改变.结果 对照组各时间点血脑屏障无开放.脑缺血再灌注3h组,血脑屏障开放,伊文思蓝少量通透血脑屏障;6、12h组开放程度和伊文思蓝通透量逐渐增加,24h组达高峰,72h组有所减弱.结论 大鼠大脑中动脉阻塞再灌注后,血脑屏障的结构和功能呈现时程性改变,掌握改变的时程性,有助于对血管源性脑水肿发生机理的理解和早期防治.

The Study on Morphological and Permeability Changes of BBB during Reperfusion after Middle Cerebral Artery Occlusion in Rats

Objective To study the ultrastructure and permeability changes of blood brain barrier(BBB) during reperfusion after middle cerebral artery occlusion in rats.Methods We observed the ultrastructure changes of BBB with Lanthanum at different time of reperfusion after middle cerebral artery occlusion in rats using mediated Longa' method,and evaluated the functional changes with content of permeated Evens Blue.Results It was found that within 3 hours of reperfusion after cerebral ischemia for 2 hours,the tight junction of BBB was opened and permeability began to increase,the changes got remarkable within 6 and 12 hours,reached its peak at 24 hours after reperfusion,Subsequently began to reduce at 72 hours. Conclusions The Morphological and permeability changes of BBB during reperfusion after middle cerebral artery occlusion in rats was dependent on time.For understanding and treating the vasogenic brain edma after ischemia,it was important to grasp the regular of those changes.