Glucuronidation of 4-methylumbelliferone and 4-hydroxybiphenyl and in vitro induction of UDP-glucuronosyltransferase 2B12-mRNA in precision-cut rat liver slices

• Published in: Experimental and toxicologic pathology : official journal of the Gesellschaft für Toxikologische Pathologie Vol. 54; no. 5; pp. 489 - 492
• Main Authors: Pissowotzki, Klaus, Glöckner, Reinhild, Müller, Dieter
• Format: Journal Article
• Language: English
• Published: Jena Elsevier GmbH 01.06.2003; Elsevier
• Subjects: 4-hydroxybiphenyl; 4-methylumbelliferone; Animals; Animals, Outbred Strains; beta-naphthoflavone; Biological and medical sciences; Biphenyl Compounds - pharmacology; Enzyme Induction; Gastroenterology. Liver. Pancreas. Abdomen; Gene Expression Regulation, Enzymologic; glucuronidation; Glucuronides - metabolism; Glucuronosyltransferase - biosynthesis; Glucuronosyltransferase - genetics; Hymecromone - pharmacology; induction; Liver - drug effects; Liver - enzymology; Liver slices; Liver. Biliary tract. Portal circulation. Exocrine pancreas; Male; Medical sciences; Microtomy; Other diseases. Semiology; phenobarbital; Rats; Rats, Wistar; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger - metabolism; RT-PCR; UGT2B12-mRNA; 4-methylumbelliferone; phenobarbital; induction; RT-PCR; Liver slices; UGT2B12-mRNA; 4-hydroxybiphenyl; beta-naphthoflavone; glucuronidation; Rat; Liver; Glycosyltransferases; Glucuronic acid conjugation; Slicing; Umbelliferone derivatives; UDP-glucuronosyltransferase; Enzyme; Induction; Transferases; Rodentia; Experimental study; In vitro; Vertebrata; Mammalia; Biphenyl derivatives; Animal; Hexosyltransferases
• ISSN: 0940-2993; 1618-1433
• DOI: 10.1078/0940-2993-00290

Fresh rat liver slices were used to demonstrate the glucuronidation of the model substrates 4-methylumbelliferone (MU) and 4-hydroxybiphenyl (HB). Both glucuronidation reactions proved to be more stable than cytochrome P450-dependent monooxygenations. After an incubation time of 48 h there was no decrease in MU glucuronidation rate, whereas HB glucuronidation was stable until 24 h, and then decreased by about 50% until 48 h. The technique of quantitative competitive RT-PCR was used to determine the expression of UDP-glucuronosyltransferase 2B12-mRNA (UGT2B12-mRNA) in precision-cut rat liver slices. Constitutive levels of UGT2B12-mRNA were measurable. Following 24 h culture of rat liver slices in the presence of phenobarbital, the level of UGT2B12-mRNA increased about twofold, which corresponds to the inducibility in vivo. The addition of beta-naphthoflavone had no influence. The results show that precision-cut liver slices are not only suitable for the detection of an in vitro induction of cytochrome P450-mRNAs, which is characterized by high induction factors, but also of poor induction effects, e.g. on UGT2B12-mRNA, provided that the respective mRNA is exactly quantified.