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: 20alpha-dihydroprogesterone, 17alpha-hydroxyprogesterone, 16alpha-hydroxyprogesterone, 5alpha-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 delta4-5-isomerase and 3beta-dehydrogenase activity by HCG was demonstrated.