OCCURRENCE OF δ5-3β-HYDROXYSTEROIDS IN ADRENAL AND TESTICULAR TISSUE

ABSTRACT Pregnenolone (3β-hydroxy-pregn-5-en-20-one) and 17α-hydroxy-pregnenolone (3β, 17-dihydroxy-pregn-5-en-20-one) have been isolated for the first time from pig adrenals, in which no trace of dehydroepiandrosterone (DHA, 3β-hydroxy-androst-5-en-17-one) could be detected. It has been possible, however, to obtain DHA from bovine testes, which in turn contained no 17α-hydroxy-pregnenolone. In view of the enzymatic reactions which androgens are known to undergo in adrenal and testicular tissue, these findings strongly support the assumption that DHA is chiefly derived from adrenal 17α-hydroxy-pregnenolone. They also provide reliable evidence in favour of the view that in both adrenal and testicular tissue two pregnenolone-dependent androgen pathways exist, the major adrenal pathway being pregnenolone→ 17α-hydroxy-pregnenolone → DHA → androst-4-ene-3,17-dione, and the major testicular pathway: pregnenolone → progesterone → 17α-hydroxy-progesterone → androstenedione.