Danazol: endocrine consequences in healthy women

Area of Science:

• Reproductive Endocrinology
• Pharmacology

Background:

• Danazol is used to treat endometriosis and other gynecological conditions.
• Its precise mechanism of action, particularly on the hypothalamic-pituitary-gonadal axis, requires further elucidation.

Purpose of the Study:

• To investigate the effects of danazol on pituitary and gonadal function in normal women.
• To determine if danazol suppresses gonadotropin secretion or directly inhibits steroidogenesis.

Main Methods:

• Seven healthy women received danazol (400 mg twice daily) for 2 months.
• Circulating levels of sex steroids, gonadotropins (LH, FSH), and prolactin were measured throughout a control cycle and treatment.
• Hormonal responses to gonadotropin-releasing hormone and estradiol valerate were assessed.

Main Results:

• Danazol inhibited ovulation in all subjects, inducing amenorrhea.
• Basal levels of gonadotropins, prolactin, and estrogen remained normal.
• Serum androgen levels and urinary 17-ketosteroid excretion increased significantly.
• Luteinizing hormone (LH) and follicle-stimulating hormone (FSH) responses to gonadotropin-releasing hormone were enhanced.
• Positive feedback of estrogen on LH release remained intact.

Conclusions:

• Danazol's mechanism does not involve suppression of pituitary gonadotropin secretion or direct steroidogenesis inhibition.
• The findings suggest danazol primarily acts at the ovarian level, impairing follicular maturation.