实验性大鼠脑缺血的病理组织学和超微结构变化

本实验观察不同时期的大鼠全脑缺血期与再灌流期神经元的选择性损害,其结果大脑皮层第Ⅲ、Ⅴ层、海马H_1段等神经元对缺血最敏感;再灌流时,膜结构改变颇为突出,还呈现严重的脑水肿等改变,讨论了发病机理。

Histopathological and Ultrastructural Changes of Brain Tissues after Experimental Complete Cerebral Ischemia in Rats

The selective vulnerability of brain tissues after 30 minutes of complete ischemia was observed 5, 15, and 30 minutes after ischemia and 15, 60, and 180 minutes after reperfusion in rats under optical and electron microscopies. It was found that the cerebral cortex especially the third and fifth lamina, the H1 segment of the hippocampus, and the Purkinje cells of the cerebellum were most liable to be damaged after ischemia. After reperfusion, the alterations of membrane system, nuclei and organelles were significant. The membraneous structures which contained a large amount of lipids were more severely damaged. At the same time cerebral edema was found, the severity of which was correlated with the intensity of histopathological and ultrastructural changes of the brain and the degree of blood brain barrier disruption.The findings suggest that oxygen free radicals and lipid peroxides may play an important role in the development of the damages in the brain mentioned above after reperfusion.