Gonadotropins and gonadotropin receptors during the perimenopause

Twenty-two perimenopausal patients (aged 47-56 years) admitted for elective abdominal hysterectomy and salpingo-oophorectomy were selected to understand better the clinical significance of increasing gonadotropin levels as an indicator of target organ responsiveness. Prior to anesthesia, blood was drawn from the patients for subsequent analyses of serum follicle-stimulating hormone (FSH), luteinizing hormone (LH) and 17beta-estradiol (E2) levels. Ovarian tissue was obtained during surgery and frozen at -70 degrees C for subsequent analyses for FSH and LH receptor content. The phase of the menstrual cycle of the patients or postmenopause was determined by serum gonadotropin and E2 levels and histological evaluation of the endometrium. Patients with no detectable FSH receptors showed significantly higher serum FSH and LH levels (4.7- and 4.3-fold, respectively) when compared to patients with detectable FSH receptors; FSH receptors were present in 27% of the patients, LH receptors were present in 68% of the patients and a negative correlation was found between serum LH levels and ovarian LH receptors. In postmenopausal patients, neither FSH receptors nor LH receptors were detectable. High serum gonadotropin levels in perimenopausal patients thus suggest the existence of low or undetectable ovarian gonadotropin receptor levels.