Abstract
Ischemic changes in small vessels, especially in capillaries, were investigated by electron microscope. Samples were taken from the ischemic foci in the thalamus of 18 dogs which were subjected to various cerebrovascular occlusions from 15 minutes to 24 hours by our method of producing thalamic infarction in dogs.
After 30 minute occlusion, swelling of perivascular astrocytic processes was seen. After 1 hour occlusion, swelling of pericytes was seen. After 2 hours occlusion, swelling of endothelial cells was seen. Blebs were found in the lumen of capillaries after 3 hours. Dehiscence of tight junctions was rarely observed after 6 hours occlusion, but after 12 hours occlusion it was frequently found in capillaries and venuoles which had succumbed to necrosis. Diapedesis from necrotic capillaries and venuoles was found in the 12 hour occlusion group. After 24 hours occlusion, numerous neutrophiles appeared within the blood vessels and some of them infiltrated into softened areas.
