Cytochemical study of alkaline phosphatase activity in microvessels of rat cerebral cortex.
Cytochemical study of alkaline phosphatase activity in microvessels of rat cerebral cortex.
复制标题
大鼠大脑皮层微血管碱性磷酸酶活性的细胞化学研究。
作者：
T. Masuzawa;H. Shimabukuro;F. Sato
本文用光镜和电镜观察了大鼠额叶皮质内微血管，并着重研究了血管壁碱性磷酸酶活性与血管内径的关系。采用Mayahara等2）的柠檬酸铅法对碱性磷酸酶进行组织化学显示。在电镜水平上，碱性磷酸酶活性的电子致密的反应产物被发现的小动脉的壁与一个中间层和那些metarterioles与单层和不完整的媒体。而2-3层中层小动脉管壁无反应。在内径6-9 μm的毛细血管壁上，碱性磷酸酶反应产物不连续地分布于内皮细胞近腔面和周细胞表面。强烈的反应产物均匀分布在与厚的基底膜接触的星形胶质细胞突起表面。而管腔直径小于5 μm的毛细血管则无反应。小静脉和静脉的壁也没有显示这种酶的活性。鉴于对脑微循环和血脑屏障生理学的兴趣日益增加，碱性磷酸酶的超微结构定位将有助于对该系统的理解。
Intracortical microvessels of the rat frontal lobe were examined by light and electron microscopy with special reference to the relationship between the localization of alkaline phosphatase activity on the walls and the luminal diameters of the vessels. The lead citrate method of Mayahara et al.2) was used to histochemically demonstrate alkaline phosphatase. At the electron microscopic level, electron dense reaction products of alkaline phosphatase activity were found on the walls of arterioles with one medial layer and in those of metarterioles with single-layered and incomplete media. However, no reaction was encountered on the walls of arterioles with 2-3 medial layers. On the walls of capillaries 6-9 μm in luminal diameter, the reaction products of alkaline phosphatase were distributed discontinuously on the abluminal surfaces of endothelial cells and on the surfaces of pericytes. Intense reaction products were distributed evenly on the surfaces of astrocytic processes in contact with the thick basal lamina. On the other hand, capillaries less than 5 μm in luminal diameter showed no reaction at all. The walls of venules and veins also displayed no activity for this enzyme. In view of increasing interest in the physiology of cerebral microcirculation and the blood-brain barrier, the ultrastructural localization of alkaline phosphatase would cbntribute to the understanding of this system.