Comparison of arterial lesions and serum lipids in spider and rhesus monkeys on an egg and butter diet

Abstract

Serum and aortic lipids and atherosclerotic lesions were studied in five spider monkeys (Ateles sp.) and three rhesus monkeys ( Macaca mulatta) after changing from a commercial chow diet to a high fat (40% of calories), high cholesterol (1 mg/cal), semisynthetic diet containing egg yolk and butter. There was a large species difference in response of serum cholesterol. After 12 weeks on the diet the mean elevation of serum cholesterol was 285 mg/100 ml for the rhesus and 17 mg/100 ml for the spider monkeys. Changes in serum cholesterol ester fatty acid patterns were also very much greater for the rhesus than for the spider monkey. Aortas and coronary arteries of the rhesus were extensively involved with sudanophilic lesions. The cholesterol and cholesterol ester content of the aortic intima was much greater in the rhesus than in the spider monkey. The proportional contribution of aortic cholesterol oleate was greater in rhesus than spider monkeys and the palmitate was lower. There were only a few sudanophilic lesions in the coronary arteries of the spider monkeys. The coronary arteries of one older rhesus monkey were extensively involved with fibrous lesions. There was no appreciable difference between species in the histologic appearance of the sudanophilic lesions.