Effects of a gonadotropin-releasing hormone agonist on progesterone formation in cultured human granulosa cells

Abstract

Abstract. Human granulosa cells from follicles of natural cycles (13 women) in mid- or late follicular phase were cultured in modified Medium-199. Human luteinizing hormone (100 μg/l), follicle-stimulating hormone (100 μg/l) and gonadotropin-releasing hormone agonist (GnRHa) (10−12 to 10−6 mol/l) alone or in combination were added to the culture medium. Medium content of progesterone was analysed. In granulosa cells obtained in the mid-follicular phase, the basal progesterone formation averaged 0.5 pg · cell−1 · (48 h)−1· FSH caused a 3-fold stimulation. GnRHa (10−6 mol/l) had a variable influence on the basal progesterone formation, whereas it consistently inhibited (40–50%) the FSH response. In granulosa cells from late follicular phase basal progesterone formation averaged 5 pg · cell−1 ·(48 h)−1 and was stimulated 3-to 6-fold by LH. GnRHa (10−6 mol/l) stimulated the basal progesterone formation and caused a tended to potentiate the LH response on progesterone formation. It is concluded that GnRHa at relatively high concentrations exerts direct effects on gonadotropin-stimulated progesterone formation of human granulosa cells and that these effects are different (inhibitory or stimulatory) dependent on the degree of follicular maturation, and/or type of gonadotropin used.