The effect of varying prolactin levels on pituitary luteinizing hormone and follicle-stimulating hormone response to gonadotropin-releasing hormone.

Seventy-one women with menstrual irregularities were investigated by measurement of basal plasma estradiol, prolactin, and gonadotropin levels. They were each given an intravenous injection of 100 microgram of gonadotropin-releasing hormone (GnRH), and both luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were measured for two hours. The women were divided into three groups on the basis of the prolactin levels: "normal," "mild elevation," and "severe elevation." For each prolactin group there was no difference in age or estradiol or basal LH and FSH levels. The pituitary response to the GnRH injection was also similar for the three groups. These data suggest that elevated prolactin levels do not interfere with pituitary gonadotropin cell function.