TISSUE CONCENTRATION OF OESTRONE, OESTRADIOL-17β AND OESTRIOL IN THE HUMAN FOETUS

Abstract

The highest tissue concentration of estrogen was found in the fetal liver and with correction for the losses indicated by recovery experiments, the mean concentrations were: 15.0 [mu]gAg estrone, 30.0 [mu]g/kg estradiol-17[beta] and 346 MgAg estriol. In the adrenals and kidneys, the bulk of estrogen was found in the form of conjugated estriol and the concentration of estrone and estradiol-17[beta] was about or beyond the sensitivity of the method used. Very little, if any, estrogen was found in the brain. The mean corrected concentrations at term of the amniotic fluid were calculated as 6.8 [mu]g/1 estrone, 4.3 [mu]g/1 estradiol-17[beta] and 945 [beta]g/1 estriol. Approximately 10% of the estriol was found in the unconjugated form. The mean corrected estrogen concentration of the umbilical cord blood was 20.3 [beta].g/kg estrone, 8.7 Kg/kg estradiol- 17[beta] and 696 [beta]g/kg estriol. Approximately 10% of the estriol and more than 50% of the estrone and estradiol-17[beta] were found in the free form. Estriol was isolated and identified by infrared spectrography from extracts of cord blood and amniotic fluid.