Response of pituitary LH and FSH to synthetic LH releasing hormone in normal subjects and patients with Sheehan's syndrome

Abstract

Serum levels of LH and FSH were determined by radioimmunoassay in seven patients with Sheehan's syndrome, eight women with normal menstrual cycles, and five normal men following intravenous injection of synthetic luteinizing hormone-releasing hormone (LH-RH) in a dose of 100 μg. The mean maximum increases of LH (M. ± S.E. mI.U./ml.) were in the following order: 279.4 ± 87.6 at the preovulatory phase, 69.2 ± 12.6 in normal males, 48.2 ± 3.5 at the midluteal phase, and 29.9 ± 4.9 at the early follicular phase. The response of serum levels of FSH was found to parallel the change in the levels of LH, but these changes were less pronounced. No response of LH and FSH to LH-RH was observed in five patients with Sheehan's syndrome while the remaining two patients showed an increase of LH around normal lower limits. These findings seem to indicate that LH-RH test is useful for the evaluation of pituitary reserve function of gonadotropin secretion.