FURTHER STUDIES OF THE METABOLISM OF OESTRADIOL IN MAN

Abstract

Oestradiol-17[beta] labeled with tritium in the a orientation of C-17 was administered intravenously to two women. Oestrone, oestradiol, oestriol and 3[alpha]-hydroxypregnan-20-one were isolated from the urine and the isotope incorporated into these metabolites was measured. The results supported the prior conclusion that oestradiol is rapidly oxidized in vivo and that oestrone serves as the immediate precursor of oestriol. A possible explanation is offered for the presence of trace quantities of isotope in oestriol and 3[alpha]-hydroxypregnan-20 one.