[Histochemical study on enzymatic barrier of the newly formed vessels in infarcts]

To investigate the properties of the vessels newly formed in cerebral infarcts, we performed enzyme histochemical study for alkaline phosphatase and gamma-glutamyl transpeptidase that are membrane enzyme of capillary endothelial cells in the brain as well as immunohistochemical study for factor VIII related antigen and laminin. Adult mongolian gerbils were used in the experiment to produce cerebral infarcts. The animals showing clear neurological signs of ischemia after occlusion of the left common carotid artery were selected. Following one hour ischemia blood flow was reperfused and the animals were allowed to grow and sacrificed at predetermined intervals ranging from two days to two years. The stainings for alkaline phosphatase and gamma-glutamyl transpeptidase were performed by Brustone method and Rutenburg method respectively, and those for factor VIII related antigen and laminin by PAP method, in frozen sections. Four days after ischemia, vessels of a slightly large size that were running irregularly with reactivity of factor VIII related antigen and circumscribed by laminin were observed in the marginal zone of the infarcts. These newly formed vessels increased in number during the second and the third week also in the center of the infarcts, and one month after ischemia began to decrease. However, a number of vessels were seen in the infarcts, whose features were comparatively similar to those of normal vessels. These vessels remained as long as for two years. The number of the vessels with alkaline phosphatase and gamma-glutamyl transpeptidase activity did not increase during the first week. They increased later during the second and third week.(ABSTRACT TRUNCATED AT 250 WORDS)