脑胶质瘤中血脑屏障的超微结构特点

CHARACTERISTIC FEATURES OF THE ULTRASTRUCTURE OF CEREBRAL GLIOMAS

8例胶质瘤病例,标本分别取自同一病例的瘤体、瘤周水肿区和邻近脑组织。瘤体和瘤周水肿区血脑屏障超微结构变化无明显差异,内皮肿胀,毛细血管腔狭小,胶面有稀疏的绒毛样突起,内皮为无孔型,胞质内胞饮泡较多,内皮紧密连接增长,细胞连接间隙增宽,基膜完整,胶质膜缺损。邻近脑组织血脑屏障未见类似变化。冷冻蚀刻技术显示,在星形细胞瘤内的星形细胞终足胶质-血管界面的质膜上,存在与钾离子通道有关的互相垂直排列的颗粒。

Specimens of 8 gliomas were taken from the tumor, peritumoral oedematous region and adjacent cerebral tissue of each patient. Blood-brain barrier in tumors and peritumoral oedematous regions had the same variations in ultrastructure. Endothelia were swellon, but not fenestrated. Endothelia had an abundance of pinocytotic vesicles, longer tight junctions and enlarged junctional clefts, and intact basement membrane. The lumina of capillaries were strictured with sparse villus-like prominences. The glial limitans outside the basement membrane of capillaries were damaged. These variations were not observed in adjacent cerebral tissues. In addtion, freeze-fracture studies showed that orthogonal arrays of panicles were clustered on the endothelium-facting membranes of astrocytes that might be potassium channels.