OESTROGEN SYNTHESIS FROM [4-14C—1,2-3H]TESTOSTERONE BY A 160000 g SUPERNATANT FROM BABOON PLACENTA AND BY POSTMICROSOMAL FRACTIONS

Abstract

SUMMARY A baboon placental homogenate was centrifuged at 160000 g for 70 min to give a microsomal fraction and a supernatant, which on further centrifugation at 260000 g for 110 min gave a first postmicrosomal fraction and a second supernatant. This supernatant was centrifuged at 260000 g for 210 min to afford a second postmicrosomal fraction and a third supernatant. The incubation of the first supernatant with [4-14C—1,2-3H]testosterone gave androstenedione, 19-hydroxytestosterone, 19-hydroxyandrostenedione, 17β-oestradiol and oestrone; incubation with the postmicrosomal supernatants yielded androstenedione only. When the two postmicrosomal fractions were incubated with the substrate, both 17β-oestradiol and androstenedione were obtained as metabolites. The losses of tritium from 17β-oestradiol and from oestrone metabolites were consistent with previous findings.