STUDIES ON THE AROMATISATION OF NEUTRAL STEROIDS IN PREGNANT WOMEN.

Abstract

ABSTRACT Androst-5-ene-3β,16α,17β-triol-7α-3H was synthesized and the metabolism of this compound was studied in two volunteers following the administration at laparotomy of a tracer dose into the intact foeto-placental circulation. The bulk of the radioactive material recovered from the placenta was in an unconjugated form. From this fraction androst-5-ene-3β,16α,17β-triol (Δ5-TRIOL), 16α-hydroxy-testosterone (16αHO-T) and oestriol (OE3) were isolated, but no labelled 16α-hydroxy-dehydroepiandrosterone (16αHO-DHA), 16α-hydroxy-androstenedione (16αHO-A), 16α-hydroxyoestrone (16αHO-OE1) or 16oxo-17β-oestradiol (16oxo-OE2) were detected. Some 90 per cent of the unconjugated and 77 to 90 per cent of the conjugated radioactive material present in the various foetal tissues was isolated as Δ5-TRIOL. Oestriol was also isolated, but only from the liver. It was present exclusively in a conjugated form. No conjugated or unconjugated 16αHO-DHA, 16αHO-OE1 or 16oxo-OE2 was detected in the foetal tissues. The data indicate that the midterm placenta extensively converts Δ5-TRIOL into 16αHO-T and some of the latter into OE3, but that neither the placenta, nor the foetus is capable of converting these ring D glycols into the corresponding ketols. Considerable quantities of OE3, but little, if any, of the 16αHO-T formed seem to be released by the placenta to the foetus.