Cellular regulation of the metabolism of androgens in rat oral mucosa: I. Effect of medroxyprogesterone acetate (MPA) on the soluble supernatant (cytosol) activating microsomal delta4-3-ketosteroid-5alpha-reductase and 17beta-hydroxysteroid oxidoreductase enzyme systems.

Soluble supernatant (cytosol) of rat oral mucosa was found to contain a factor accelerating the activity of microsomal delta4-3-ketosteroid-5alpha-reductase and 17beta-hydroxysteroid oxidoreductase enzymes metabolizing testosterone. Systemic administration of medroxyprogesterone acetate further increased this cytosolic activity.