Inhibitory effect on pig testicular 20 beta-hydroxysteroid dehydrogenase by various inhibitors of steroid metabolizing enzymes
Nakajin, S.; Ohno, S.; Aoki, M.; Shinoda, M.
Yakugaku Zasshi Journal of the Pharmaceutical Society of Japan 108(12): 1219-1222
The inhibitory effect of various inhibitors of steroid metabolizing enzyme against 20.beta.-hydroxysteroid dehydrogenase (20.beta.-HSD) purified from the pig testes was investigated. The dehydrogenase activity was considerably inhibited by spironolactone, SU 10603 and cyanoketone. Those compounds showed a concentration-dependent and competitive inhibitory effect and the inhibition constants (Ki) were 11.2 .mu.M for spironolactone, 22.3 .mu.M for SU 10603 and 42.8 .mu.M for cyanoketone. However, 20.beta.-HSD activity was not inhibited by SU 8000, 1-(o-chlorophenyl)-1-(p-chlorophenyl)-2,2-dichloroethane, aminoglutethimide and SKF 525A.