An ultrastructural study of developing cerebral infarction following bilateral carotid artery occlusion in spontaneously hypertensive rats.

An ultrastructural study of cerebral infarcts in spontaneously hypertensive rats 1--5 h after bilateral carotid artery occlusion was performed. The alteration of the neocortex consisted of shrinkage of the neurons surrounded by swollen astrocytic processes. Distension of the rough endoplasmic reticulum of the neuronal cytoplasm appeared early, while changes of the mitochondria were slight. Though there appeared slight to moderate perivascular astrocytic swelling, endothelial swelling was rare and there was no severe narrowing of the capillary lumen. There were no filling defects of colloidal carbon injected to the blood vessels of the ischemic brains. Ischemic neuronal alterations were proved to develop in the absence of severe morphological changes of the microvasculature in the developing cerebral infarcts in the present experimental model.