ESTIMATION OF OESTRONE SULPHATE, OESTRADIOL-17β AND OESTRONE IN PERIPHERAL PLASMA: CONCENTRATIONS DURING THE MENSTRUAL CYCLE AND IN MEN

Abstract

SUMMARY A method for the determination of oestrone sulphate, oestradiol-17β and oestrone in human peripheral plasma is described, and the accuracy, specificity, precision and sensitivity of each analysis is defined. Free oestrogens were extracted from plasma with ether. Oestradiol-17β was isolated by chromatography on silica gel. Oestrone, similarly purified, was reduced to oestradiol-17β and rechromatographed. Oestrone sulphate in the residual plasma was solvolysed and the oestrone liberated was isolated and reduced to oestradiol-17β. All three fractions were estimated separately by competitive protein binding with rabbit uterine cytosol. Manipulative losses were assessed from recovery of [3H]oestradiol-17β and [3H]oestrone added to the plasma and of [3H]oestrone sulphate added to the ether extracted plasma. The concentration of oestrone sulphate in peripheral plasma of six men greatly exceeded that of oestradiol-17β or oestrone. The mean concentrations were respectively, 72, 2·3 and 3·6 ng/100 ml. Analysis of samples collected daily during a menstrual cycle from each of two women also showed that the concentration of oestrone sulphate was much greater than that of oestradiol-17β or oestrone. Changes in the concentrations of all three oestrogens occurred at similar times in the cycle. At mid-cycle, the mean concentrations were: oestrone sulphate, 308 ng/100 ml; oestradiol-17β, 57 ng/100 ml; oestrone, 15 ng/100 ml.