Gonadotropin-releasing hormone agonist reduces aromatase cytochrome P450 and cyclooxygenase-2 in ovarian endometrioma and eutopic endometrium of patients with endometriosis

AIMS: To investigate whether the GnRH agonist may reduce aromatase P450 and COX-2 in the eutopic endometrium of patients with endometriosis and ovarian endometrioma. MATERIALS AND METHODS: Endometrial specimens and ovarian endometrioma were obtained from 15 women with endometriosis undergoing laparoscopic surgery. The stromal cells of the eutopic endometrium and ovarian endometroma were cultured in the presence of the GnRH agonist (leuprolide acetate 0, 1, 5 and 10 microM) for 24 h. To investigate the effects of the GnRH agonist on the eutopic endometrium in vivo, biopsy samples of the endometrium (n = 5) among the patients who underwent laparoscopy were obtained after GnRH agonist therapy. The protein production of aromatase cytochrome P450 and COX-2 was examined by Western blot. RESULTS: Proteins of aromatase P450 and COX-2 were reduced in the eutopic endometrium of patients with endometriosis treated with the GnRH agonist for 3 months. The stromal cells in the culture of endometrial explants and ovarian endometrioma which were treated with the GnRH agonist reduced the aromatase P450 and COX-2. CONCLUSION: The GnRH agonist reduced aromatase P450 and COX-2 by direct action on the eutopic endometrium of patients with endometriosis and ovarian endometrioma.