The Localization of Alkaline Phosphatase Activity in Cerebral Blood Vessels.

Since the development of the first histochemical techniques for demonstrating non-specific alkaline phosphatase activity (Gomori, 1939; Takamatsu, 1939) there have been a number of reports of activity in the endothelium of blood vessels of the mammalian nervous system. Differences in the site and intensity of endothelial staining in the nervous systems of different species have been described but there are no reports of attempts to follow the pattern of alkaline phosphatase activity from arteries to veins in the cerebral vascular tree. Recently we have found evidence of localized areas of alkaline phosphatase activity in the vascular system of muscles and other tissues (Romanul and Bannister, 1962), and in view of the distinctive structural and functional properties of cerebral blood vessels it seemed important to examine in detail their alkaline phosphatase activity.