OESTROGEN RECEPTORS IN HUMAN UTERINE TISSUE

Abstract

SUMMARY The uptake and retention of [3H]oestradiol-17β by human uterine and muscle tissue was studied in vitro by incubation of tissue slices. The binding characteristics of immature rat and adult human tissue were compared. Human endometrium had a greater affinity for tritiated oestradiol than human myometrium. Human uterine tissues bound less [3H]oestradiol-17β than rat uterine horns. The difference in retention between a target and non-target tissue in the human tissue was much smaller than in the rat, although still highly significant. Binding was inhibited by low concentrations of oestradiol-17β, U-11100A and hexoestrol, but was not inhibited by the same concentrations of oestrone, oestriol or oestradiol-17α. Freezing the uterine tissue resulted in a loss of specific binding activity. Binding was shown to vary with different uterine specimens. There was a significant difference in [3H]oestradiol-17β retention between the proliferative and secretory phases of the menstrual cycle. The highest endometrial retention was found in endometrial carcinoma.