Pituitary gonadotropin responses to synthetic luteinizing hormone-releasing hormone in patients with typical and atypical polycystic ovary disease.

Synthetic luteinizing hormone-releasing hormone (LH-RH) was administered intravenously to 17 women with polycystic ovary disease (PPCO), 16 women with hypothalamic amenorrhea (HA), and nine women with normal cycles. The serum levels of follicle-stimulating hormone (FHS) and luteinizing hormone (LH) were measured at frequent intervals before and after LH-RH injection. The PCO patients were arbitrarily divided into two groups on the basis of ovarian morphology. The eight patients with large, "typical" PCO's (Type I) showed a greater LH response and a lower FSH response to LH-RH than did the nine patients with smaller, "atypical" PCO's (Type II). The LH response in Type I co was also greater than that in HA, but the FSH response in both types of PCO was significantly less than that in HA. The gonadotropin responses to LH-RH in Type I PCO were quite similar to those occurring in normal women during the two to three days prededing ovulation. The results suggest that excessive LH secretion and/or impaired FSH secretion may be etiologically significant in PCO but do not clearly differentiate whether the stimulus for this pattern of gonadortopin secretion occurs at the hypothatamic or pituitary level.