Enhanced Disparity of Gonadotropin Secretion by Estrone in Women with Poly cystic Ovarian Disease*

Abstract

The disassociation between serum LH and FSH levels in polycystic ovarian disease (PCO) has been attributed to chronic acyclic estrogen production characterized by a predominance of circulating estrone (E₁). This study was designed to determine whether the administration of estrone benzoate (E₁B) modulates gonadotropin release in PCO. In five normal women studied during the early follicular phase of a control and subsequent treatment cycle, daily LH and FSH levels were unaltered by EiB administered from days 2 to 6. Gonadotropin responses to LRF given on day 7 were similar during control and treatment cycles. In seven patients with PCO, the mean LH concentration (25.7 ± 0.7 mlU/ml) and the daily pattern of release were unchanged by E₁B administered for 14 days. In contrast, a progressive decline in FSH occurred in each subject. Mean FSH levels decreased significantly from a pretreatment value of 11.3 ± 0.2 to 9.3 ± 0.9 mlU/ml by day 2 (P < 0.05) and 7.2 ± 1.2 mlU/ml by day 14 (P < 0.005) of E₁B administration. The LH response to LRF in PCO was significantly greater than that observed in the normal subjects, whereas responses before, during, and after EiB administration were similar. The FSH responses to LRF in PCO subjects were comparable to those of the normal subjects. These data indicate that the administration of EiB to PCO subjects reduces FSH levels without altering LH release, thereby enhancing the disparity of gonadotropin secretion encountered in this syndrome. This finding is consistent with the hypothesis that impairment of FSH release by chronic acyclic estrogen production derived from nonglandular aromatization of circulating androgen could in large part be responsible for anovulation in PCO.