Formation of bile acid glucosides and dolichyl phosphoglucose by microsomal glucosyltransferases in liver, kidney and intestine of man

Abstract

Formation of glucosides of the bile acids chenodeoxycholic, ursodeoxycholic, deoxycholic and hyodeoxycholic acids has been detected in microsomes from human liver, kidney and intestinal mucosa. Hepatic and extrahepatic bile acid glucosyltransferase activities were characterized with respect to kinetic parameters and other catalytic properties. Whereas no marked organ-specific differences in the affinities of individual bile acids toward hepatic and extrahepatic glucosyltransferases were observed, microsomes from extrahepatic sources showed twice to 5-times the maximal rates of bile acid glucosidation estimated with microsomes from liver. In addition to bile acid glucoside formation, microsomes from human liver, kidney and intestinal mucosa catalyzed the synthesis of dolichyl phosphoglucose acting as natural glucosyl donor in bile acid glucosidation.