Effect of the inhibition of "NADH-diaphorase" activity on the ultrastructural localization of 3 beta-hydroxysteroid dehydrogenase]

The NADH-ferricyanide oxidoreductase ("NADH-diaphorase") activity can be inhibited selectively with 0.5 mM p-chloromercuribenzoate, and the reduction of the potassium ferricyanide can be restored with an exogenous electron carrier (PMS). These operations do not affect the localization of the final precipitate of copper ferrocyanide which results from 3beta-hydroxysteroid dehydrogenase activity.