Effect of probucol on cholesterol metabolism in the rat.

The effects of probucol treatment on cholesterol metabolism were examined in rats. Male Sprague-Dawley rats were divided into 3 groups: one group was given 0.25% probucol containing chow diet, one group was given 0.25% clofibrate containing chow diet, and the third group was fed chow diet alone. All groups of rats were maintained on these regimens for 4 weeks before killing. Probucol treatment resulted in a decrease in plasma cholesterol and cholesterol 7 alpha-hydroxylase activity. Clofibrate treatment resulted in a reduction of plasma cholesterol, hepatic HMG-CoA reductase and cholesterol 7 alpha-hydroxylase activities. The fecal excretion of neutral and acidic sterols were decreased significantly in the probucol or clofibrate-treated rats. In the bile there was a decrease in the concentration of total bile acids. These results suggest the mechanism for hypocholesterolemic action of probucol to be different from that of clofibrate.