Acute pericytic response to cerebral ischemia

Abstract It has been suggested that the pericyte, through its close relationship to the capillary unit, is involved in several functional roles. In some pathological states the cell has been reported to transform into a phagocytic form and become mobile. The role of pericytic involvement in the ischemic brain has not been previously reported. In this study of effects of temporary occlusion of the middle cerebral artery in the baboon, the pericytes were found to contain abundant “lysosomal-like” material in the shorter vascular occlusive periods whereas in the animals with longer ischemia, extensive intrapericytic edema was observed within the brain parenchyma. Pericytic susceptibility to edema was found to be less than that of the astrocytes. No pericytes were observed penetrating the surrounding basement membrane or transforming into structures suggestive of phagocytes. The pathological pericytic changes were quite independent of those appearing in the endothelial cells.