PATHWAYS IN THE BIOSYNTHESIS OF ANDROGENS IN THE POSTMENOPAUSAL OVARY IN VITRO

Abstract

ABSTRACT Postmenopausal ovarian tissue homogenates were incubated with [7α-3H]-pregnenolone as substrate. In six independent incubations only androstenedione and testosterone were found. These androgens were isolated by column and thin-layer chromatography and identified by derivative formation and recrystallization to constant specific activity. In one of the incubations, the homogenate was divided into 3 parts. From one part incubated with [7α-3H] pregnenolone, androstenedione and testosterone were identified. From the second and third parts of the homogenate which were incubated with [4-14C]progesterone and [4-14C] testosterone respectively, the substrates were recovered unmetabolized at the end of the incubation. From these results it is deduced that the postmenopausal ovary can not aromatize androgens to oestrogens and that in this particular tissue the Δ5 pathway is the preferred route of androstenedione production.