Metabolism of (4-14C)progesterone and (7alpha-3H)pregnenolone by human ovaries perfused in vitro

Nine human ovaries were perfused in vitro with [4-14C] progesterone and in addition one ovary with [7-3H] pregnenolone. From the perfusate unchanged progesterone and five different metabolites were isolated: 20α-dihydroprogesterone, 17α-hydroxyprogesterone, 16α-hydroxyprogesterone, 5α-pregnane-3,20-dione and 4-androstene-3,17-dione. In the ovarian tissue saturated pregnane derivatives were the main metabolites. When [3H] pregnenolone and [14C] progesterone were perfused simultaneously a stimulation of Δ4–5-isomerase and 3β-dehydrogenase activity by HCG was demonstrated.