Endogenous Hypercholesterosis in Rabbits Fed a Fat-free Purified Diet and the Effect of Unsaturated Lipid

Serum and hepatic cholesterol levels of male, adult rabbits were determined at the end of a 12-week period of ad libitum maintenance with cholesterol-free purified diets. The purified diets contained either no lipid or 5, 10 or 20% of corn oil. The total cholesterol concentration of the serum increased in all groups. The group receiving no lipid exhibited a greater cholesterol rise in the serum than the groups receiving corn oil. The increase in serum cholesterol of rabbits fed corn oil did not appear to be a function of the lipid content of the diet. The total hepatic cholesterol concentration was increased in fat deficiency, was lowest at the minimum fat concentration, and increased with increasing fat content of the diet. This increase was characterized by a greater increase in the esterified fraction than in the free fraction.