THE UPTAKE OF [6,7-3H]OESTRADIOL BY THE NORMAL HUMAN FEMALE REPRODUCTIVE TRACT

Abstract

SUMMARY The uptake of [6,7-3H]oestradiol by the reproductive tract was studied in 18 non-pregnant women who were undergoing hysterectomy for conditions not associated with an abnormal endometrium. A single s.c. injection of 50 μc [6,7-3H]oestradiol (specific activity, 182 μc/μg.) was given 2 hr. before hysterectomy. Tissue samples were dissolved in 5 n-alkali and their radioactivity content determined by liquid scintillation counting. Total and free steroid (ether soluble) radioactivities in the plasma were also determined. The existence of an essentially normal menstrual cycle in these patients was confirmed by histological examination of tissue samples and, in some cases, by determinations of urinary pregnanediol. Urinary total radioactivity was within the normal range, except in one case, thus confirming normal oestrogen metabolism. The radioactivity content of the tissues of the reproductive tract was well above that attributable to their plasma content. In some cases the uptake by different regions of the endometrium varied considerably. In the follicular phase of the menstrual cycle uptake was higher than that in the luteal phase. Vaginal and cervical epithelium showed variable uptake but in general it was lower than that for endometrium. Cell fractionation studies showed that, in general, proportionally more of the endometrial radioactivity was associated with the nuclei in the follicular phase than in the luteal phase.