[Steroid hormone concentrations in human endometrium and plasma (author's transl)]

Concentrations of progesterone (P), 20 alpha-dihydroprogesterone (20P), 17-hydroxyprogesterone (17P), androstenedione (A), estrone (E1) estradiol (E2) in endometrium and peripheral blood taken simultaneously from normally menstruating women in the course of hysterectomy were determined by radioimmunological assay. The mean concentration of P in the endometrium in the follicular phase was significantly lower than that in the luteal phase, whereas the mean E2 content in the follicular phase was significantly higher than that of the luteal phase. Six steroids examined were divided into 3 groups according to the ratio of the concentrations in the endometrium vs. plasma. The E2 and E1 groups were of high ratios and 17P and A groups were low ratios in both the follicular and the luteal phase. The concentrations of P and 20P in the endometrium vs. plasma in the luteal phase were correlated well. The results suggest that the steroid concentrations in the endometrium were related to the steroid receptors, steroid metabolisms and plasma steroid concentrations. Thus simultaneous determination of steroid hormone contents in plasma and endometrium seems to provide useful information concerning the functional abnormalities of endometrium.