Lipid Depletion in Atheromatous Coronary Arteries in Rhesus Monkeys after Regression Diets

Abstract

Lipids were measured in the coronary arteries of monkeys on an atherogenic diet and in the arteries of matched monkeys on the atherogenic diet followed by regression diets. Cholesterol content was 51 mg/g dry weight in the arteries of monkeys with atheromatosis; after 40 months on the regression diets it was 18 mg/g. Cholesteryl ester was 69% lower and free cholesterol 53% lower after the regression diets. Decreases in triglycerides and phospholipids were not significant. The cholesterol content of the arteries of two monkeys autopsied after 20 months on the regression diets was close to the mean value after 40 months. The data show that cholesterol in both its free form and its ester form is depleted from experimentally induced coronary atheromatosis by dietary regression regimens. The data also suggest that most of the cholesterol depletion occurs during the first half of regression; the susceptibility of the residual excess arterial cholesterol to mobilization from the vessel wall by dietary means is questionable.