Human Chorionic Gonadotropin Stimulation of Estradiol Production and Androgen Antagonism of Gonadotropin-Stimulated Responses in Cultured Human Granulosa-Luteal Cells*

Abstract

Baseline and gonadotropin-stimulated estradiolproduction were examined in long term cultures of human granulosa-luteal cells isolated from women undergoing in vitro fertilization. Estradiol production declined by 70% during the first 48 h in culture and was minimally stimulated by the addition of hCG to the culture medium. During subsequent culture from 48–120 h estradiol production was significantly increased over control levels by hCG concentrations greater than 0.1 IU/ml.Incubation with testosterone stimulated estradiol production 100-fold in the presence and absence of gonadotropin hCG(0.01–10 IU/ml) stimulated a 3- to 13-fold increase in progesterone production. However, at hCG concentrations greater than 1 IU/ml, coincubation with testosterone (10⁻⁷ M) significantly inhibited progesterone production. Dihydrotestosterone also inhibited progesterone production, but to a lesser extent than testosterone. Freshly isolated granulosa-luteal cells specifically bound small amounts of [¹²⁵I]hCG (125I]hCG binding by 100%. In 5-day cultures, specific [¹²⁵I]hCG binding nearly doubled from 52,000 cpm/10⁵ cells in control cultures to 87,000 cpm/10⁵ cells in cultures treated with hCG (0–5 IU/ml). At the highest concentration of hCG (5 IU/ml), testosterone (10⁻⁷ M) significantly inhibited the amount of [¹²⁵I] hCG specifically bound. In summary, estradiol production in long term cultures of granulosa-luteal cells appears to be gonadotropin dependent. In addition, the presence of testosterone (10⁻⁷ M) antagonizes hCG-stimulated progesterone and LH receptor production by these cells.