Stereoselective glucuronidation of carvedilol in human liver and intestinal microsomes

Nobumitsu Hanioka, Sawako Tanaka, Yushi Moriguchi, Shizuo Narimatsu

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

Background and Purpose: Carvedilol is used clinically as a β-adrenoceptor antagonist for the treatment of chronic heart failure and is primarily metabolized into glucuronides by UDP-glucuronosyltransferase (UGT). In this study, the stereoselective glucuronidation of carvedilol by the human liver and intestinal microsomes was examined using racemate and enantiomers. Methods: Carvedilol glucuronidation activities at substrate concentrations of 1-1,000 μmol/l in human liver and intestinal microsomes were determined by high-performance liquid chromatography with fluorescence detection, and the kinetic parameters were estimated. Results: The activities of S-glucuronidation toward racemic and enantiomeric carvedilol in liver microsomes were higher than those of R-glucuronidation at all substrate concentrations examined. In intestinal microsomes, the activities of S-glucuronidation from racemic and enantiomeric carvedilol at ≤100 μmol/l substrates were higher than those of R-glucuronidation, whereas the glucuronidation activities at ≥200 μmol/l substrates exhibited the opposite stereoselectivity (R > S) compared with those at ≤100 μmol/l substrates. The activities of R-and S-calvedilol glucuronidation from racemate and enantiomers in the liver and intestinal microsomes were decreased at substrate concentrations of ≥100 or 200 μmol/l, and the kinetics at substrate concentrations of 1-100 and 1-1,000 μmol/l fitted with Michaelis-Menten and substrate inhibition models, respectively. The stereoselectivities of CLint values for carvedilol glucuronidation followed by Michaelis-Menten and substrate inhibition models were R < S for liver microsomes and R S for intestinal microsomes. Conclusion: These findings demonstrate that the stereoselectivity of carvedilol glucuronidation was different between human liver and intestinal microsomes, and suggest that the difference is due to the tissue-specific expression of UGT isoforms involved in the glucuronidation of carvedilol.

Original languageEnglish
Pages (from-to)117-124
Number of pages8
JournalPharmacology
Volume90
Issue number3-4
DOIs
Publication statusPublished - Oct 1 2012

Keywords

  • Carvedilol
  • Human intestinal microsomes
  • Human liver microsomes
  • Stereoselective glucuronidation
  • UDP-glucuronosyltransferase

ASJC Scopus subject areas

  • Pharmacology

Fingerprint Dive into the research topics of 'Stereoselective glucuronidation of carvedilol in human liver and intestinal microsomes'. Together they form a unique fingerprint.

  • Cite this