Electron Microscopic Observations on the Aortic Tunica Intima in Rats Fed High-Cholesterol Diet

Abstract

Effect of the diet containing high-cholestrol and high-fat was studied on aortic tunica intima in rats. The purpose of this study was to investigate diet-induced ultrastructral change of the aorta in the experimental animals by scanning and transmission electron microscopy. Male Wistar-strain rats weighing about 120g were kept for 5 months on a semi purified diet containing 5% cholesterol and 40% non-salted butter as experimental animals (cholesterol-fed rats).The other rats fed commertial laboratory ration served as control.The results were as follows: 1) By scanning electron microscopic observations, the most conspicuous ultrastructural findings in the cholesterol-fed rats were a formation of many wrinkles on the endothelial surface and change of endothelial form.In addition, numerous leukocytes and a certain number of platelets attached to the endothelial surface. 2) By transmission electron microscopic observations, it was found that fat-containing cells (so-celled foam cell) or immature type of the foam cell at subendothelium of the intima in cholesterol-fed rats. These morphologic change suggest that diet-induced hypercholesterolemia might be a factor of endothelial injury which would serve as possible initiating events in atherosclerosis.