GROWTH-HORMONE ENHANCES ESTRADIOL PRODUCTION FOLLICLE-STIMULATING HORMONE-INDUCED IN THE EARLY-STAGE OF THE FOLLICULAR MATURATION

Objective: To investigate the ability of GH to increase the steroidoge nic response of the ovary to FSH in the early stage of human follicle development in vivo. Design: Ovarian sensitivity to FSH and/or GH duri ng the early follicular phase of the human menstrual cycle was evaluat ed in a prospective study. Setting: Normal human volunteers in the Dep artment of Obstetrics and Gynecology, Universita Cattolica Sacro Cuore . Patient(s): Twenty-four normal patients with normo-ovulatory cycles and tubal factor infertility. Intervention(s): Pure urinary FSH (75 IU ) or saline were injected IV in the early follicular phase with of wit hout a pretreatment with human GH (0.1 IU/kg IM for 3 days), Main Outc ome Measure(s): Plasma levels of LH, FSH, E(2), and T in samples colle cted for a period of 26 hours after saline or FSH IV injection. Result (s): Follicle-stimulating hormone injection increased E(2) and E(2):T stimulated area under the curve (AUC) with respect to saline administr ation. Moreover, the E(2) secretion was increased significantly in the group treated with GH plus FSH as compared with that found in the gro up receiving FSH alone. Growth hormone itself was unable to increase a ny steroidogenic response by ovary in terms of both E(2) and E(2):T AU C values. Conclusion(s): The results of present study demonstrate in v ivo a synergistic effect of GH on the FSH-induced follicular steroidog enesis, suggesting a potential relevance of GH in the reproductive bio logy.