Cycle and age-related changes in corticotropin-releasing hormone levels inhuman endometrium and ovaries

Corticotropin-releasing hormone (CRH) is synthesized in most female reprodu ctive tissues such as the ovaries and the uterus. In the non-pregnant uteru s, it is mainly produced by epithelial cells of the endometrium. Recent in vitro experimental findings show that endometrial CRH is under the positive control of progesterone, participating in the decidualization process of e ndometrial stroma and the progression of blastocyst implantation. CRH is al so produced in the thecal compartment of the human ovary, controlling ovari an steroid hormone biosynthesis. In the present study we compared the conce ntration of immunoreactive CRH (ir-CRH) in biopsies from proliferative and secretory human endometria, and from pre- and postmenopausal human ovaries. We found that the concentration of ir-CRH was significantly higher in the secretory (92 +/- 8 pg/mg protein; n = 10) than the proliferative (75 +/- 9 pg/mg protein; n = 12; p < 0.05) endometria. This observation supports the experimental in vitro findings associating endometrial CRH in intrauterine phenomena of th secretory phase of the menstrual cycle (decidualization an d implantation). Additionally, we have shown that the concentration of ir-C RH was significantly higher in the premenopausal (125 +/- 12 pg/mg protein; n = 14) than the postmenopausal (100 +/- 12 pg/mg n = 12; p < 0.05) ovarie s, suggesting that ovarian CRH is related to normal ovarian function during the reproductive lifespan.