A method for the determination of UDP-glucuronosyltransferase activity toward arylcarboxylic acids

Anal Biochem. 1993 Aug 1;212(2):487-97. doi: 10.1006/abio.1993.1358.


A fast and reliable method for the assay of UDP-glucuronosyltransferase (UGT) activity toward aglycones containing a carboxylic acid function is described. The procedure involves incubation with UDP-[U-14C]-glucuronic acid, the common substrate for the reaction, solid-phase separation of the radiolabeled acylglucuronides and unreacted cofactor, and quantification by liquid scintillation counting. The technique was validated for each of the seven substrates tested by reversed-phase HPLC, and was then applied successfully to the determination of optimal conditions for the activation of the carboxylic acid-UGT, and the estimation of kinetic constants for the glucuronidation of clofibric acid, 2-naphthylacetic acid, naproxen, and 4,4,4-triphenylbutanoic acid in rat liver microsomes. From the results obtained, we believe that this is an assay which, with only minor modification, could be applied to a wide range of carboxylic acid substrates for which, until now, specific and sensitive assays have been largely unavailable.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anti-Inflammatory Agents, Non-Steroidal / metabolism
  • Carbon Radioisotopes
  • Carboxylic Acids / metabolism*
  • Chromatography, Liquid
  • Clofibric Acid / metabolism
  • Enzyme Activation
  • Glucuronates / metabolism
  • Glucuronosyltransferase / metabolism*
  • Ibuprofen / metabolism
  • Kinetics
  • Male
  • Methods
  • Naproxen / metabolism
  • Phenylpropionates / metabolism
  • Rats
  • Rats, Wistar
  • Reproducibility of Results
  • Uridine Diphosphate Glucuronic Acid / metabolism


  • Anti-Inflammatory Agents, Non-Steroidal
  • Carbon Radioisotopes
  • Carboxylic Acids
  • Glucuronates
  • Phenylpropionates
  • Uridine Diphosphate Glucuronic Acid
  • Clofibric Acid
  • Naproxen
  • Glucuronosyltransferase
  • pirprofen
  • Ibuprofen