Immunoexpression of aromatase cytochrome P450 and 17β-hydroxysteroid dehydrogenase in women's ovaries after menopause

Background: Menopause results in a lack of regular menstrual cycles, leading to the reduction of estrogen production. On the other hand, ovarian androgen synthesis is still present at reduced levels and requires expression of several steroidogenic enzymes. Methods: This study was performed on 104 postmenopausal women hospitalized due to uterine leiomyomas, endometriosis, and/or a prolapsed uterus. Patients were divided into three groups depending on the time from menopause. Group A patients experienced menopause 1-5 years before enrollment in the study (42 women). Group B included women who had their last menstruation 5-10 years before the study (40 women). Group C consisted of 22 women who were more than 10 years past menopause. Hysterectomy or removal of the uterine corpus with adnexa was performed during laparotomy. We evaluated the expression of aromatase cytochrome P450 (CYP 19) and 17 beta-hydroxysteroid dehydrogenase (17 beta HSD) by employing immunohistochemistry. Results: Activity of 17 beta-HSD and CYP19 was demonstrated in the cytoplasm of stromal cells of postmenopausal ovaries, epithelium cells coating the ovaries, vascular endothelial cells, and epithelial inclusion cysts. However, overall expression of both 17 beta-HSD and CYP 19 decreased with time after menopause. Conclusion: Demonstration of the activity of the key enzymes of ovarian steroidogenesis, CYP 19 and 17 beta-HSD, confirms steroidogenic activity in the ovaries of postmenopausal women. Nevertheless, ovarian steroidogenic activity decreases with time, and its significant decrease occurs 10 years after menopause.