Cholesterol kinetics in the normal rat aorta, and the influence of different types of dietary fat

Abstract

Summary Groups of rats, maintained on cholesterol-free diets containing either 30 % safflower oil or 30 % coconut oil, were given single intragastric doses of (4-14C) -cholesterol. The ensuing rise in radioactivity of aorta cholesterol was substantially higher in the coconut-oil group than in the safflower-oil group. The two groups were nearly identical in regard to plasma-cholesterol concentrations, plasma-cholesterol specific activitytime curves, aorta-cholesterol concentrations, and in vitro synthesis of cholesterol from acetate by the aorta. It was therefore concluded that coconut-oil feeding had resulted in faster transfer of cholesterol from plasma into the wall of the aorta, in comparison with safflower-oil feeding, under conditions of identical plasma-cholesterol concentrations. It was estimated that transfer from plasma accounted for roughly 3/4 of the cholesterol in the wall of the aorta in the safflower-oil group. The data did not permit an estimate of this parameter in the animals on coconut oil. Analysis of the fatty-acid constituents of plasma cholesterol esters and triglycerides revealed a distinct tendency in the direction of the composition of dietary fat. Plasma phosphatide fatty acids were influenced only slightly by diet.