Angiochemical and tissue cholesterol changes of Macaca fascicularis fed an atherogenic diet for 3 years.

Angiochemical and tissue cholesterol changes were investigated in Macaca fascicularis fed either an atherogenic containing 1 mg cholesterol/Cal or a control diet for 3 years. The thoracic and abdominal aortas and the carotid and femoral arteries were visually examined for the extensiveness of atherosclerosis and analyzed for lipid, collagen, elastin, and mineral content. Cholesterol accumulation in other tissues was assessed by measuring concentrations in liver, kidney, skin, and tendon. The cynomolgus macaques fed the atherogenic diet had between 77 and 97% of the intimal surface of all arteries studied affected with atherosclerotic lesions. The arteries of animals fed the atherogenic diet were between 1.6–2.5 times heavier than the arteries of control animals. This increased weight was attributed largely to collagen and elastin. When animals fed the atherogenic diet were compared with controls, significant increases in arterial total cholesterol, esterified cholesterol, phospholipid, calcium, phosphorus, and magnesium were seen. The liver, skin and tendon, but not the kidney, had significant increased concentrations of total and esterified cholesterol compared to control tissues. Comparison of our findings with the results of other studies of nonhuman primates indicates that the atherosclerotic plaques induced in the cynomolgus macaques are most nearly comparable to atherosclerosis in man, primarily because of the marked accumulation of mineral and connective tissue components.