Estrogen and progestogen binding site concentrations in human endometrium and cervix throughout the menstrual cycle and in tissue from women taking oral contraceptives

Abstract

Estrogen and progestogen binding site concentrations in human cervix and endometrium were measured throughout the menstrual cycle in tissue from cycling women and women taking oral contraceptives. The estrogen binding site concentrations in endometrium were higher in the proliferative and early secretory phase (days 1–17) when compared to the later secretory phase (days 18–28), while the cervical concentrations remained constant throughout the cycle. In contrast, both endometrial and cervical levels of progestogen binding sites were higher in the proliferative than in the secretory phase. Cervices from women taking oral contraceptives exhibited estrogen and progestogen binding site concentrations in the range found for proliferative phase tissues. The data from this and previous studies support the suggestion that the regulation of female sex hormone-mediated events in the human cervix occurs via receptors similar in many aspects to those found in other target tissues.