Response of ovarian steroid secretion to the intrinsic gonadotropin release caused by the administration of synthetic luteinizing hormone-releasing hormone.

During gynecologic laparotomies, both ovarian and peripheral venous blood specimens were collected simultaneously, and follicle-stimulating hormone (FSH), luteinizing hormone(LH), estradiol, and progesterone were measured in each sample by means of the radioimmunoassay technique before and after the administration of synthetic LH-releasing hormone (LH-RH). The FSH levels rose significantly 30 minutes after the LH-RH injection, while the LH values had already increased significantly at 15 minutes. A significant decrease of the average FSH AND LH levels during the follicular phase and the average LH levels during the luteal phase was observed in the ovarian as compared to the peripheral venous blood. The estradiol levels in the ovarian venous blood made a prompt and significant increase almost in parallel with the gonadotropin release. During the luteal phase, the progesterone concentrations in the ovarian and peripheral venous blood increased significantly. It is considered that the human ovary responds quite promptly to an abrupt release of intrinsic FSH and LH caused by the administration of synthetic LH-RH and secretes estradiol and progesterone immediately.