title: 17 Beta-estradiol inhibits the oxidative metabolism of U937 cells indirectly via lymphocytes.
abstract: The effect of 17 beta-estradiol (E) on the oxidative metabolism of U937 cells was studied. E had no direct effect on the proliferation, surface adherence, or luminol-enhanced luminescence (LEL) of the U937 cells. Exposure of U937 cells to lymphocyte-conditioned medium (LCM) and 1,25-dihydroxyvitamin D3 allowed a maximal LEL response by cells stimulated with phorbol myristate acetate. In contrast, LCM from lymphocytes exposed to E (LCM-E) did not stimulate LEL to the same extent as did an equal volume of LCM. Increasing the E concentration in the lymphocyte medium was associated with a dose-dependent reduction in the LEL response of the U937 cells. Mixing equal quantities of LCM and LCM-E significantly decreased LEL levels. LEL stimulated by LCM, gamma-interferon, or differentiation-inducing factor was reduced by the presence of LCM-E. The inhibitory action of LCM-E was reversible and metabolite specific. 17 alpha-E produced an effect that was only one tenth the magnitude of the E effect. These findings indicate that E can modulate the differentiation of phagocytes indirectly by altering the synthesis and/or secretion of lymphokines.
mesh_terms: D002117:Calcitriol / Q000494:pharmacology; D002454:Cell Differentiation / Q000187:drug effects; D002460:Cell Line; D003470:Culture Media; D004958:Estradiol / Q000494:pharmacology*; D006801:Humans; D008163:Luminescent Measurements; D008165:Luminol / Q000494:pharmacology*; D008214:Lymphocytes / Q000187:drug effects / Q000502:physiology*; D008222:Lymphokines / Q000494:pharmacology; D010084:Oxidation-Reduction; D011724:Pyridazines / Q000494:pharmacology*; D013755:Tetradecanoylphorbol Acetate
chemical_list: D003470:Culture Media; D008222:Lymphokines; D011724:Pyridazines; D004958:Estradiol; D008165:Luminol; D002117:Calcitriol; D013755:Tetradecanoylphorbol Acetate