Choleretic properties of ursodeoxycholic acid and chenodeoxycholic acid in dogs

Choleretic effects and properties of ursodeoxycholic and chenodeoxycholic acids given orally were investigated in comparison with dehydrocholic acid in conscious dogs with cholecystectomy. Ursodeoxycholic acid as well as chenodeoxycholic acid increased the bile flow and the concentrations of phospholipid, cholesterol and bile acids in the bile. After administration of either ursodeoxycholic acid or chenodeoxycholic acid, a great amount of each bile acid appeared in the bile. Ursodeoxycholic and chenodeoxycholic acids increased the outputs of phospholipid, cholesterol and bilirubin in the bile. On the other hand, dehydrocholic acid markedly decreased the concentrations and outputs of all the above materials in the bile, despite a considerable increase in the bile flow. After administration of dehydrocholic acid, 3alpha, 7alpha-dihydroxy-12-keto-cholanoic acid appeared in the bile instead of dehydrocholic acid. The results suggest that ursodeoxycholic and chenodeoxycholic acids are transported into the bile from the hepatic cells where they produce a choleresis due to the bile acid-dependent mechanism. Dehydrocholic acid is metabolized in the liver and the metabolites produced hydrocholeresis.