title: Inhibition of hepatic 17 beta- and 3 alpha-hydroxysteroid dehydrogenases by antiinflammatory drugs and nonsteroidal estrogens.
abstract: Antiinflammatory agents and estrogens have been tested as inhibitors of two isozymes of guinea pig liver testosterone 17 beta-dehydrogenase (NADP) 1.1.1.64) and rat liver 3 alpha-hydroxysteroid dehydrogenase (EC 1.1.1.50). Antiinflammatory steroids and estradiols were highly inhibitory to 3 alpha-hydroxysteroid dehydrogenase and one isozyme of testosterone 17 beta-dehydrogenase, respectively, but nonsteroidal antiinflammatory agents and nonsteroidal estrogens such as hexestrol, dienstrol, diethylstilbestrol and zearalenone showed potent inhibitions on all the enzymes. Although the inhibitory potency of indomethacin for one isozymes of testosterone 17 beta-dehydrogenase and 3 alpha-hydroxysteroid dehydrogenase decreased with changing pH from 9.7 to 7.0, that of the nonsteroidal estrogens for all the enzymes was little affected by pH. No additive effect in double inhibitor experiments with indomethacin and the nonsteroidal estrogens was observed, and the compounds were all competitive inhibitors with respect to steroidal substrate. The results suggest that there is a very similar region in substrate binding sites of the enzymes.
mesh_terms: D015067:17-Hydroxysteroid Dehydrogenases / Q000037:antagonists & inhibitors*; D015096:3-Hydroxysteroid Dehydrogenases / Q000037:antagonists & inhibitors*; D045002:3-alpha-Hydroxysteroid Dehydrogenase (B-Specific); D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology; D004968:Estrogens, Non-Steroidal / Q000494:pharmacology*; D006168:Guinea Pigs; D006914:Hydroxysteroids / Q000494:pharmacology; D066298:In Vitro Techniques; D008099:Liver / Q000201:enzymology; D051381:Rats
chemical_list: D000893:Anti-Inflammatory Agents; D000894:Anti-Inflammatory Agents, Non-Steroidal; D004968:Estrogens, Non-Steroidal; D006914:Hydroxysteroids; D015067:17-Hydroxysteroid Dehydrogenases; D015096:3-Hydroxysteroid Dehydrogenases; C032690:3-alpha-(17-beta)-hydroxysteroid dehydrogenase (NAD(+)); D045002:3-alpha-Hydroxysteroid Dehydrogenase (B-Specific)