CYCLICAL VARIATION IN ENDOMETRIAL ESTROGEN AND PROGESTERONE RECEPTORS IN WOMEN WITH NORMAL MENSTRUATION AND DYSFUNCTIONAL UTERINE BLEEDING

The majority of women with dysfunctional uterine bleeding ovulate and have normal cyclical changes in gonadotrophins, oestrogen and progesterone. To investigate whether the hormonal milieu at tissue level is different in these women, we measured the endometrial concentration of oestrogen and progesterone receptors at various stages of the menstrual cycle in women with normal menstrual loss (less-than-or-equal-to 80 ml/cycle, n = 40) and dysfunctional uterine bleeding (> 80 ml/cycle, n = 44). Menstrual blood loss was measured using the alkaline haematin method. Receptor levels were measured in nuclear and cytosol extracts of endometrium using solid phase immunoassays, based on monoclonal antibodies against receptor protein, which measure the bound and unbound fractions of the receptors. We found endometrial oestrogen (P < 0.01) and progesterone (P < 0.05) receptor levels were higher in the late secretory phase in women with dysfunctional uterine bleeding compared with women with normal menstrual loss. The receptor levels were the same in both groups at all other stages of the menstrual cycle. There was a strong positive correlation between the level of late secretory endometrial oestrogen receptor and measured menstrual blood loss (r = 0.8 1, P < 0.0 1). Increased local oestrogen effect is present in the premenstrual endometrium in dysfunctional uterine bleeding.