Oestrogen and progestogen receptor content in human endometrium.

The cyclic process of proliferation, secretory differentiation, (pre)decidualization, menstrual degeneration and regeneration in premenopausal endometrium is controlled by oestrogens and progestogens, and is mediated through binding to their specific receptors. Oestrogen (ER) and progestogen receptor (PR) presence and concentration indicate not only hormonal influence on the specific cells but also the capacity to respond to these hormones. ER and PR concentrations in endometrium vary with the phases of the menstrual cycle, but their relationship to cyclic changes in histomorphology and hormonally modulated tissue factors in the specific cell types has not been extensively studied. There is some evidence that these changes reflect functional processes resulting, at least in part, from interactions between the different endometrial cell types [1].