An assessment of udp-glucuronosyltransferase induction using primary human hepatocytes

Drug Metab Dispos. 2004 Jan;32(1):140-8. doi: 10.1124/dmd.32.1.140.

Abstract

Uridine diphosphate glucuronosyltransferases (UGTs) catalyze the glucuronidation of a wide range of xenobiotics and endogenous substrates. However, there is a lack of information concerning the response of human UGTs to inducers, and this observation prompted the current investigation. The glucuronidation of estradiol (3- and 17-positions), naphthol, propofol, and morphine (3- and 6-positions) was assessed against a battery of recombinant human UGTs to determine selective glucuronidation reactions for induction studies. The potential induction of the glucuronidation of estradiol at the 3-position, naphthol, propofol, and morphine at the 3-position was subsequently investigated in cultured primary human hepatocytes against a range of prototypic inducers including dexamethasone, 3-methylcholanthrene (3-MC), phenobarbital, rifampicin, and omeprazole. Treatment with 3-MC induced estradiol-3-glucuronidation (up to 2.5-fold) in four of five donors investigated. Statistically significant increases in naphthol glucuronidation (up to 1.7-fold) were observed following treatment with carbamazepine. UGT1A9-mediated propofol glucuronidation was induced by phenobarbital (up to 2.2-fold) and rifampicin (up to 1.7-fold). However, treatment with alpha-naphthoflavone and tangeretin resulted in a decrease in propofol glucuronidation (30% of control values). Statistically significant induction of morphine-3-glucuronidation was observed in at least three donors following treatment with phenobarbital, rifampicin, and carbamazepine. Each UGT isoform investigated displayed a distinct induction profile. Although statistically significant increases in glucuronidation were observed for each reaction studied, the level of induction was less than that observed for CYP1A2 or CYP3A4 and exhibited a large interdonor variability. The clinical relevance of the induction responses obtained in this study is unclear.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Cells, Cultured
  • Child
  • Child, Preschool
  • Chromatography, High Pressure Liquid
  • Cytochrome P-450 CYP1A1 / metabolism
  • Cytochrome P-450 CYP1A2 / biosynthesis
  • Cytochrome P-450 CYP3A
  • Cytochrome P-450 Enzyme System / biosynthesis
  • Enzyme Induction / drug effects*
  • Estradiol / metabolism
  • Female
  • Glucuronides / metabolism
  • Glucuronosyltransferase / biosynthesis*
  • Hepatocytes / enzymology*
  • Humans
  • Hydroxytestosterones / metabolism
  • Isoenzymes / biosynthesis
  • Male
  • Mass Spectrometry
  • Middle Aged
  • Morphine / metabolism
  • Naphthols / metabolism
  • Propofol / metabolism
  • Recombinant Proteins / biosynthesis
  • Substrate Specificity

Substances

  • Glucuronides
  • Hydroxytestosterones
  • Isoenzymes
  • Naphthols
  • Recombinant Proteins
  • Estradiol
  • 6 beta-hydroxytestosterone
  • Morphine
  • Cytochrome P-450 Enzyme System
  • CYP3A protein, human
  • Cytochrome P-450 CYP1A1
  • Cytochrome P-450 CYP1A2
  • Cytochrome P-450 CYP3A
  • CYP3A4 protein, human
  • Glucuronosyltransferase
  • Propofol