Ursodeoxycholic acid. Effects on sterol metabolism in rats.

Sterol balance studies using isotopic and chromatographic techniques were performed in rats fed diets supplemented with ursodeoxycholic acid. Compared to controls, ursodeoxycholic acid dramatically altered sterol metabolism. Ursodeoxycholic acid was absorbed and circulated in the enterohepatic circulation. The biliary bile acid composition was significantly altered with ursodeoxycholic acid the predominant biliary bile acid (67%). Cholesterol absorption was depressed by 34%; bile acid synthesis was depressed by 30%; however, cholesterol balance was significantly increased. It is apparent that the effects of ursodeoxycholic acid on sterol metabolism are different in several respects from chenodeoxycholic acid.