Effects of Progesterone Receptor Blockers on Human Granulosa-Luteal Cell Culture Secretion of Progesterone, Estradiol, and Relaxin

Abstract We have developed culture methods for human luteinizing granulosa cells (GLC) that support the timely and dynamic secretion of estrogen (estradiol-17β; E2), progesterone (P4), and relaxin (Rlx) in patterns that mimic serum hormone concentrations during the luteal phase of the menstrual cycle. Additional hCG, to simulate rescue of the corpus luteum, prevented the normal decline in GLC hormone production. To test the importance of the P4 receptor in P4 production, GLC were treated in vitro with two P4 receptor antagonists. Human GLC received one of two hCG support protocols: a Baseline group simulating the normal luteal phase or a Rescue group simulating early pregnancy. Baseline and Rescue groups were treated with either RU-486 or HRP2000 either early or late in the cell culture period. The effects of treatments or control on ovarian steroid and peptide hormone production were determined (significant difference was P < 0.05). In the Rescue group, late treatment resulted in an immediate and dramati...