ELECTRON MICROSCOPIC STUDIES ON CHOLESTEROL-INDUCED CEREBRAL ATHEROSCLEROSIS IN COCKERELS.

Abstract

Cerebral atherosclerotic lesions in cockerels were studied with aid of light and electron microscopes. Twelve birds were given cholesterol in addition to the standard broiler feed. Twelve other birds serving as controls received the feed alone. The cholesterol-fed birds exhibited alterations in the endothelial cells of the leptomeningeal and brain tissue vessels. The endothelial cells showed vacuoles containing crescent-shaped lipid bodies and the subendothelial space contained a granular-fibrillary substance and lipid-filled macrophages. The contours of the basement membranes were somewhat granular. The internal elastic lamina occasionally seemed split and fragmentary and had lost its normal fibrillar structure. The collagen fibrils were more evenly distributed than in the vessel walls of the control group and followed a more irregular course, but the periodicity was normal. Vacuolation of the perinuclear parts of smooth muscle cells was rare. Especially in the hypothalamic region, small lipid-containing vacuoles were observed within the cytoplasm of the cells of the brain tissue proper. From the fact that some of the vacuoles were completely translucent and others contained electron-dense lipid droplets of various sizes, it was inferred that these may represent different stages of transformation of the chemical state of the lipids.