Original Article

Induction of Hepatic Microsomal UDP-Glucuronosyltransferase Activity in Nifedipine Treated Rats

Young Sook Hong, Young-Sook Pae
Author Information & Copyright
Department of Biochemistry, College of Medicine, Ewha Womans University, Korea.
Department of Pharmacology, College of Medicine, Ewha Womans University, Korea.

Copyright ⓒ 1990. Ewha Womans University School of Medicine. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Published Online: Jul 24, 2015

Abstract

UDP-Glucuronosyltransferase(UDPGT) activity was studies in hepatic microsomal preparation from rats treated with nifedipine. The substrates 1-naphthol, P-nitrophenol, 4-methyl-umbelliferone and bilirubine were used. With 1-naphthol, nifedipine 2 and 4 weeks treatment caused 6- and 7.3-fold, respectively, increase in activity over the control value. With 4-methylumbelliferone, nifedipine 2 and 4 weeks treatment caused 5- and 6-fold increase in activity over the control value. With P-nitrophenol, nifedipine 2 and 4weeks treatment caused both approximately 3-fold increase in activity over the control value. However bilirubin-UDPGT activity was not affected by this inducer effects of nifedipine on the hepatic monooxygenase system in rats were investigate. P-Nitroanisole-O-demethylase, NADPH-cytochrome C reductase activity and cytochrome P-450 content in nifedipine treated rats were significantly increased to 390, 290 and 150% of control rats, respectively.

The selectivity of nifedipine of UDP-glucuronosyltransferase was investigated in rat liver microsomes and compared with their effect on monooxygenase reactions. Similart o 3-meth-lycholanthrene-type selectively stimulated the glucuronidation induced both UDPGT1 and monooxygenase activity, probably through a common receptor protein.