GLYCOPROTEIN HORMONES AND THEIR COMMON ALPHA-SUBUNIT STIMULATE PROLACTIN PRODUCTION BY EXPLANT CULTURES OF HUMAN LEIOMYOMA AND MYOMETRIUM

OBJECTIVE: The purpose of this study was to examine the effect of the gonadotropins luteinizing hormone, follicle-stimulating hormone, and human chorionic gonadotropin on prolactin production by human leiomyomas and myometrium. A secondary goal was to explore the effect of thyroid-stimulating hormone and the alpha-subunit common to all these glycoproteins in the same system. STUDY DESIGN: Explant cultures were established, and harvested medium was assayed for total protein and prolactin. Dose-response studies were performed with follicle-stimulating hormone, luteinizing hormone, and human chorionic gonadotropin. A second set of studies was conducted with a single dose of human chorionic gonadotropin, thyroid-stimulating hormone, and alpha-subunit. RESULTS: Gonadotropins, thyroid-stimulating hormone, and alpha-subunit all stimulated prolactin production in both leiomyoma and myometrium. Prolactin production was significantly higher in leiomyoma than in myometrium. A positive effect of time, dose, and gonadotropin treatment on prolactin production was seen in each tissue. There was no treatment effect on total protein secretion. CONCLUSIONS: All four glycoprotein hormones and their common alpha-subunit stimulate prolactin production. This appears to be a specific effect.