Experimental cerebral infarction in the dog. Ultrastructural study of microvessels in subacute cerebral infarction.

Abstract

Large-sized infarctions of the cerebral hemisphere (LSICH) were experimentally induced in 20 dogs by injecting two silicone cylinders through the right cervical internal carotid artery. The LSICH models were perfused with heparinized saline and fixed with 1.5% glutaraldehyde solution through the contralateral carotid artery 7 days after the embolization. Mercox® was then injected manually. The brains were immediately removed, and specimens were obtained from the basal ganglia and the ectosylvian gyrus. Regenerated microvessels were observed within the necrosis in the basal ganglia. The regenerated microvessels had an irregular, “bead-like” surface, and formed anastomosed networks. The regenerated capillaries had double basement membranes and endothelia with abundant ribosome and increased pinocytotic vesicles. It is suggested that the regenerated capillaries had immature blood-brain barriers of increased permeability. It is thought that the brain functions of this area are reversible. The microvessels within the vasogenic edema in the corticomedullary junctional area of the ectosylvian gyrus had smooth surfaces, and formed normal capillary networks, but their perivascular spaces were dilated with edematous fluids.