脳血液関門とグリアの病理学

Pathology of blood-brain barrier and glia

I．血液脳関門

　脳毛細血管内皮細胞は水や若干の物質を除き，血液から脳への多くの分子の透過性を制限し，steady stateの条件下でも多くの物質は脳組織水と平衡せず，血液脳関門は複雑な生理的現象と考えられている。しかし，脈絡叢，下垂体，tuber cinereum，area postrema，paraplysis，松果体，preoptic recessには関門機能は観察されない。

Summary

　Rat brain tissue including the capillary has been studied with freeze-fracture technique. The pau-city of luminal pinocytotic vesicles and the presence of zonula occludens in the endothelial cells are characteristic of cerebral capillary and considered as a morphological representation of blood-brain barrier. Under physiological and pathological conditions, the pinocytotic vesicles increase in number and the tight junction becomes leaky.