title: beta-Glucuronidase-resistant bilirubin glucuronide isomers in cholestatic liver disease--determination of bilirubin metabolites in serum by means of high-pressure liquid chromatography.
abstract: "Direct reacting bilirubin" in serum of patients with cholestatic liver disease and in serum of bile duct-ligated rats consists of a complex mixture of bilirubin metabolites. These metabolites were studied by means of high-pressure liquid chromatography. Bilirubin glucuronides in normal bile are beta-glycosidic 1-O-acyl conjugates which are completely hydrolyzed on incubation with beta-glucuronidase. Cholestatic serum contains glucuronide and non-glucuronide bilirubin metabolites. The glucuronides were only partially hydrolyzable with beta-glucuronidase. Compernolle et al. [11] showed that the 1-O-acyl bond of bilirubin glucuronides is labile and prone to migrate from the C1 position at the glucuronosyl residue to positions C2, C3 and C4. The isomerisation products are non-beta-glycosidic, beta-glucuronidase-resistant conjugates. The main beta-glucuronidase-resistant conjugates in cholestatic serum were characterized as: non-beta-glycosidic bilirubin monoglucuronide, non-beta-glycosidic diglucuronide and a diglucuronide isomer with beta-glycosidic and non-beta-glycosidic glucuronosyl groups. Moreover, a substantial amount of bilirubin monoglucoside monoglucuronide was detected in cholestatic human serum.
mesh_terms: D000818:Animals; D001663:Bilirubin / Q000031:analogs & derivatives* / Q000097:blood; D002779:Cholestasis / Q000097:blood*; D002851:Chromatography, High Pressure Liquid; D005966:Glucuronidase / Q000378:metabolism; D006801:Humans; D007536:Isomerism; D008107:Liver Diseases / Q000097:blood*; D008251:Macaca; D051381:Rats; D013552:Swine
chemical_list: C016266:bilirubin glucuronate; D005966:Glucuronidase; D001663:Bilirubin