title: Several distinct enzymes catalyze 20alpha-hydroxysteroid dehydrogenase activity in mouse liver and kidney.
abstract: The effects of flavonoids and quinones on NADPH- and NADH-dependent 20alpha-hydroxysteroid dehydrogenase (20alpha-HSD) activities were examined in cytosolic fractions from the liver and kidney of mice. Judging from the data for the inhibition of NADPH- and NADH-dependent 20alpha-HSD activities by flavonoids and quinones, enzyme catalyzing renal NADPH-dependent 20alpha-HSD activity was found to be distinct from enzyme(s) catalyzing hepatic NADPH- and NADH-dependent 20alpha-HSD activities. Sulfobromophthalein (SBP) had little ability to inhibit hepatic NADPH-dependent 20alpha-HSD activity and bromophenol blue (BPB) exhibited a weak activation against the enzyme activity, whereas SBP and BPB were potent and moderate inhibitors, respectively, of hepatic NADH-dependent 20alpha-HSD activity. Thus, enzyme catalyzing hepatic NADPH-dependent 20alpha-HSD activity appeared to be distinct from enzyme catalyzing hepatic NADH-dependent 20alpha-HSD activity. The data for the pH profiles of hepatic NADPH- and NADH-dependent 20alpha-HSD activities also led us to the conclusion. Based on these results, we propose the possibility that several distinct enzymes catalyze NADPH- and NADH-dependent 20alpha-HSD activities in cytosolic fractions from the liver and kidney of mice.
authors.affiliation: Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Kumamoto 862-0973, Japan. yorishig@gpo.kumamoto-u.ac.jp
authors.forename: Yorishige
authors.initials: Y
authors.lastname: Imamura
authors.forename: Misa
authors.initials: M
authors.lastname: Ohtaguro
authors.forename: Hideaki
authors.initials: H
authors.lastname: Shimada
mesh_terms: D043607:20-alpha-Hydroxysteroid Dehydrogenase / Q000378:metabolism*; D000818:Animals; D016227:Benzoquinones / Q000494:pharmacology*; D002384:Catalysis; D003600:Cytosol / Q000201:enzymology; D004789:Enzyme Activation; D005419:Flavonoids / Q000494:pharmacology*; D066298:In Vitro Techniques; D007668:Kidney / Q000201:enzymology*; D008099:Liver / Q000201:enzymology*; D008297:Male; D051379:Mice; D009249:NADP / Q000378:metabolism / Q000494:pharmacology; D010635:Phenolphthaleins / Q000494:pharmacology*
chemical_list: D016227:Benzoquinones; D005419:Flavonoids; D010635:Phenolphthaleins; C004532:quinone; D009249:NADP; D043607:20-alpha-Hydroxysteroid Dehydrogenase