Growth hormone enhances estradiol production follicle-stimulating hormone-induced in the early stage of the follicular maturation

Abstract

To investigate the ability of GH to increase the steroidogenic response of the ovary to FSH in the early stage of human follicle development in vivo. Ovarian sensitivity to FSH and/or GH during the early follicular phase of the human menstrual cycle was evaluated in a prospective study. Normal human volunteers in the Department of Obstetrics and Gynecology, Università Cattolica Sacro Cuore. Twenty-four normal patients with normo-ovulatory cycles and tubal factor infertility. Pure urinary FSH (75 IU) or saline were injected IV in the early follicular phase with or without a pretreatment with human GH (0.1 IU/kg IM for 3 days). Plasma levels of LH, FSH, E2, and T in samples collected for a period of 26 hours after saline or FSH IV injection. Follicle-stimulating hormone injection increased E2 and E2:T stimulated area under the curve (AUC) with respect to saline administration. Moreover, the E2 secretion was increased significantly in the group treated with GH plus FSH as compared with that found in the group receiving FSH alone. Growth hormone itself was unable to increase any steroidogenic response by ovary in terms of both E2 and E2:T AUC values. The results of present study demonstrate in vivo a synergistic effect of GH on the FSH-induced follicular steroidogenesis, suggesting a potential relevance of GH in the reproductive biology.