Pregnenolone and pregnenolone sulfate metabolism by human fetal testes in vitro.

}lomogenates of testes from human fetuses of 12-16 weeks gestation were incubated in vitro with pregnenolone-4-14C and pregnenolone-7-3Hsulfate. Dehydroepiandrosterone sulfate and pregnenediol sulfate, each bearin~ the tritium label only, were identified in the conjugated fraction. Progesterone, 17~-hydroxyprogesterone, 17a-hydroxypregnenolone, dehydroepiandrosterone, androstenedione and testosterone, each bearinm both a tritium and 14C-label, were identified in the organic fraction. In a similar incubation, with pregnenolone-7-3H-sulfate-35S as substrate, the direct conversion to 17a-hydroxypregnenolone sulfate was demonstrated. The presence of slight sulfatase activity was also noted. The direct metabolism of steroid sulfates and the presence of sulfatase activity in this fetal tissue and the possible significance of these findings in the developing male fetus are discussed.