EXPERIMENTAL STUDY Actions of gonadotropin-releasing hormone antagonists on steroidogenesis in human granulosa lutein cells

Objective: GnRH antagonists have recently been introduced for the prevention of premature LH surges during controlled ovarian hyperstimulation (COH). We have here investigated whether the GnRH antagonists cetrorelix and ganirelix exert effects on ovarian steroidogenesis. Since there is some controversy about the action of GnRH agonists in the human ovary we also tested the effect of triptorelin on steroid production in cultured human granulosa lutein cells. Methods: Cells were obtained from patients treated with different protocols of COH. In addition to gonadotropins they received triptorelin, cetrorelix, ganirelix or no GnRH analogue. Results: Such in vivo treatment did not result in significant effects of triptorelin or the two GnRH antagonists on spontaneous or human chorionic gonadotropin (hCG)-stimulated steroidogenesis. To exclude the possibility that the in vivo treatment might not affect in vitro steroid production because of low or absent peptide activity, we performed in vitro treatments with triptorelin, cetrorelix and ganirelix for up to 96 h. However, these treatment paradigms did not influence basal or hCG-stimulated steroid production. Conclusions: We conclude that GnRH antagonists do not exert any significant effects on ovarian steroidogenesis in vitro and therefore their introduction into protocols of COH is unlikely to impair ovarian function. European Journal of Endocrinology 144 677–68