Prolactin Directly Inhibits Basal as well as Gonadotropin-Stimulated Secretion of Progesterone and 17β-Estradiol in the Human Ovary*

Abstract

An ovarian perifusion technique was used to determineif there is a direct suppressive effect of PRL on humangonadal steroid secretion. Ovarian tissue from nine patients wasexamined. Ovine PRL (0.1–10 IU/ml) directly suppressed progesteroneand 17β-estradiol secretion by human ovaries. hCG(1–10 IUβml) stimulated both progesterone and 17β-estradiolsecretion. Simultaneous administrationof PIUL. (5–10 IUβml)suppressed the stimulatory effect of hCG. The ovaria tissueobtained froma hyperprolactinemic patient di not respond tohCG. These results indicate that PRL inhibits both basal andgonadotropin-stimulated ovarian steroid secretion by humanovaries and that this may be one cause of the hypogonadismassociated with hyperprolactinemia. (J Clin Endocrinol Metab54: 1246, 1982)