Effects of prolactin on progestin secretion by human granulosa cells in culture

Concentrations of human prolactin (hPrl) greater than or equal to 600 ng/ml produced inhibition of progestin production in cultures of granulosa cells pooled from follicles of women stimulated with clomiphene citrate-human chorionic gonadotropin (hCG). However, cells collected from follicles of human menopausal gonadotropin (HMG)-hCG-treated patients did not demonstrate a significant reduction in progestin secretion in response to hPrl. We conclude that high concentrations of hPrl can result in inhibition of steroidogenesis, but the expression of the inhibitory effects of Prl depends upon the hormonal treatments used to stimulate follicular growth.