[The effects of canrenone K (soldactone) on the adrenocortical steroidogenic enzymes in the bovine adrenal gland].

The effects of canrenone K (Soldactone) on 3 beta-hydroxysteroid dehydrogenase, 11 beta-hydroxylase and 18-hydroxylase activities were determined in vitro using isolated mitochondrial and microsomal fractions of the bovine adrenal glands. There was dose-related inhibition of 3 beta-hydroxysteroid dehydrogenation in the concentration between 10(-8) M and 10(-3) M, and 11 beta-hydroxylation and 18-hydroxylation in the concentration between 10(-7) M and 10(-3) M, respectively. The concentration of 50% inhibition of 3 beta-hydroxysteroid dehydrogenase activity was 8.5 X 10(-7) M and those of 11 beta-hydroxylase and 18-hydroxylase activities were 5 X 10(-5) M and 6 X 10(-6) M, respectively. NADPH added to a mitochondrial fraction or NAD to a microsomal fraction had no effect on the inhibition of conversion in the presence of canrenone K. The results indicate that canrenone K inhibited 3 beta-hydroxysteroid dehydrogenase in the pharmacological dose, 11 beta-hydroxylase and 18-hydroxylase in a higher concentration, and with the exception of NADPH or NAD, it may inhibit the generating system directly.