大鼠脑缺血再灌注后血脑屏障超微结构的改变

目的：研究大鼠脑缺血再灌注后电镜超微结构血脑屏障的特异改变。方法：采用线栓法制成大鼠大脑中动脉闭塞（MCAO）局灶性缺血2h再灌注24h模型。利用电镜技术研究脑缺血再灌注后电镜超微结构血脑屏障的特异改变。结果：在脑微血管内皮细胞核固缩，内皮细胞连接间隙和通透性增加，有的可见连接内皮细胞的基质和基膜的完整性缺失，微血管周围胶质细胞的伪足肿胀、进行性退变，微血管腔狭窄。白毛细血管内皮细胞向管腔内伸出许多突起。结论：局灶性脑缺血再灌注后24h血脑屏障的超微结构改变，可能对血液和神经元之间的营养传递有益。这可能是代偿修复和血管再生的机制之一。

The Ultrastructure Changes of Blood Brain Barrier after Cerebral Ischemic Reperfusion in Rats

Objective: To study the ultrastructure changes of blood brain barrier after cerebral ischemic reperfusion in rats. Methods: Models were induced by focal ischemia for 2 hours with middle cerebral artery occlusion (MCAO) by filament and 24 h reperfusion. The ultrastructure changes of blood brain barrier after cerebral ischemic reperfusion were observed by transmission electron microscopic technology. Results: The nucleus of endothelial cell shrinked in microvessels, the connected space of endothelial cells and permeability increased, and the integrity of endothelial cell matrix and the basement membrane lost. The end-feet of astrocyte around the micro-vessel swelled and regressive degenerated, and microvascular canals became narrow. There were many processes from blood capillary endothelial cells extended to the lumen. Conclusion: The changes after focal cerebral ischemic reperfusion may improve the nutrition transport between blood and neuron, and this may be one of the mechanisms of compensation and regeneration of new vessels.