Gestrinone

Gestrinone is a synthetic steroid occasionally used to treat endometriosis. The common disease endometriosis is characterized by the presence of endometrial tissue outside the uterus which affects approximately 10% of premenopausal women. It acts centrally on the hypothalamic-pituitary system to suppress release of lutenizing hormone (LH) and follicle-stimulating hormone (FSH), thus reducing estrogen synthesis. It also binds to androgen (AR), progesterone (PR), and estrogen (ER) receptors in the human endometrial tissue but not to steroid hormone binding globulin or corticord-binding globulin. Gestrinone binds to AR and PR with EC₅₀ values of approximately 20 and 30 nM, respectively. These values reflect approximately 5-6 fold lower affinity than testosterone and progesterone, the natural AR and PR ligands, for these receptors.