The hypothalamic-pituitary-ovarian axis in patients with endometriosis is suppressed by leuprolide acetate but not by danazol

OBJECTIVE: To investigate the effects of leuprolide acetate (LA), a GnRH agonist (GnRH-a), and of danazol on the hypothalamic-pituitary-ovarian axis in patients with endometriosis. DESIGN: Ten patients were divided into LA and danazol treatment groups. MEASURES: Serum levels of E2, immunoreactive and bioactive LH, pulsatility of LH, and gonadotropins release by GnRH. Changes in serum E2 levels by hMG administration during LA treatment. RESULTS: Serum E2 level decreased to near castrated levels during the LA treatment, while it remained unchanged during the danazol treatment. Leuprolide acetate administration resulted in a significant suppression of the serum level of bioactive LH, of the pulsatility of LH release, of the pituitary response to GnRH injection, and of the elevation in the serum E2 level by hMG administration, but danazol treatment did not show these suppressive effects. CONCLUSION: Our results suggest that the hormonal actions of LA and danazol on endometriosis are different from each other, especially in the suppression of serum E2 level.