Reduction of the Potency of Luteinizing Hormone by Estrogen

Abstract

DISPARITIES between biologic and immunologic potency estimates of several peptide hormones have been observed.^{1 , 2} The biologic implication of these differences is uncertain. Differences in estimates of the potency of serum luteinizing hormone have emerged with the advent of in vitro bioassays for small samples. Using a rat interstitial-cell testosterone assay,³ Dufau et al. have shown that the ratio of bioactive to immunoreactive luteinizing hormone was lower in menstruating women than in men, post-menopausal women and girls with gonadal dysgenesis.^{3 , 4} They postulated that serum estrogen may be responsible for reducing the potency of luteinizing hormone, as reflected by the lower ratio . . .