Effect of hexachlorobenzene on enzymes of the steroid metabolism in rat liver.

Adult female Wistar rats were fed with a diet containing 0.05% hexachlorobenzene. On the 60th day of this treatment the specific activities of NADPH: delta 4-3-oxosteroid-5 alpha-reductase and the 3-hydroxysteroid dehydrogenases in rat liver microsomes were diminished compared to control rats. The cytoplasmatic 5 beta-reduction was higher in HCB treated rats than in control rats. These alterations of the steroid metabolism lead to increased formation of 5 beta-H-steroids which are known to be inducers of the porphyrin biosynthesis.