Influence of cholesterol feeding and dietary restriction on cholesterol absorption in rabbits.

Plasma cholesterol and cholesterol absorption were measured in rabbits given either a standard or cholesterol-rich diet which were fed either ad libitum or reduced to 50% of the control ration. The results confirmed the aggravating effect of dietary restriction on the plasma cholesterol response to cholesterol feeding. Hypercholesterolemia was doubled when cholesterol feeding was associated with reduced dietary intake. The percentage of cholesterol absorbed increased significantly in cholesterol-fed rabbits on normal caloric ration, while dietary restriction had no effect on this parameter either with the standard or the cholesterol-rich diet. These data indicate that the mechanisms by which plasma cholesterol increases in response to cholesterol feeding involve increased cholesterol absorption. Nevertheless the aggravating effect of dietary restriction cannot be attributed to increased cholesterol absorption.