Induction of atherosclerosis in rats fed a high-cholesterol diet containing beta-aminopropionitrile for a short period

Abstract

Atherosclerotic lesions were induced in the aorta, particularly aortic arch, of rats fed a 1.5% cholesterol diet supplemented with 0.15% β-aminopropionitrile (BAPN) for six weeks. BAPN is a chemical lathyrogen known to interfere with the formation of elastin and collagen cross-links. Histopathological observation revealed the dissecting aneurysm in the lesions of the aorta. Intense fibrous proliferation in the media and foam cells in the media as well as adventitia were also observed. Aortic cholesterol levels (mainly esterified cholesterol) remarkably increased. The serum cholesterol levels markedly increased while the serum high density lipoprotein (HDL)-cholesterol level markedly decreased. Lecithin : cholesterol acyltransferase (LCAT) activity also notably decreased. A distinct decrease in very low density lipoprotein and HDL, particularly HDL2, was demonstrated by the electrophoretic technique on polyacrylamide gel. These changes in the aorta and serum cholesterol levels and LCAT activity were not as great in rats fed a diet supplemented with 0.15% BAPN or 1.5% cholesterol alone. These studies suggest that synergism of the arterial wall injury by BAPN and the abnormal lipid metabolism by cholesterol feeding induces a lipid accumulation in the aorta, which leads to the development of atherosclerotic lesions.