CYCLICAL VARIATION IN ENDOMETRIAL ESTROGEN AND PROGESTERONE RECEPTORSIN 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 progeste rone. To investigate whether the hormonal milieu at tissue level is di fferent in these women, we measured the endometrial concentration of o estrogen and progesterone receptors at various stages of the menstrual cycle in women with normal menstrual loss (less-than-or-equal-to 80 m l/cycle, n = 40) and dysfunctional uterine bleeding (> 80 ml/cycle, n = 44). Menstrual blood loss was measured using the alkaline haematin m ethod. Receptor levels were measured in nuclear and cytosol extracts o f endometrium using solid phase immunoassays, based on monoclonal anti bodies against receptor protein, which measure the bound and unbound f ractions of the receptors. We found endometrial oestrogen (P < 0.01) a nd progesterone (P < 0.05) receptor levels were higher in the late sec retory phase in women with dysfunctional uterine bleeding compared wit h 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 endom etrial oestrogen receptor and measured menstrual blood loss (r = 0.8 1 , P < 0.0 1). Increased local oestrogen effect is present in the preme nstrual endometrium in dysfunctional uterine bleeding.