[Effect of the superoxide radical on lymphocyte proliferation stimulated by a mitogen].

Administration of superoxide dismutase or a complex of divalent copper with lysine to human and mice lymphocyte cultures was shown to prevent from the lymphocyte proliferative response to concanavalin A stimulation. The inhibition grade dependence on the inhibitor concentration in culture medium was studied. It is concluded that active oxygen forms produced by macrophages may be factors defining the value of proliferative response of lymphoid cells under mitogen stimulation.

[Suppressive effect of the blast cells of AKR strain mice on antibody formation in vivo and lymphocyte proliferation in vitro].

Blast cells obtained from the "erythropoietic spleen" of FG-stimulated young mice and cells accumulating in the spleens of preleukemic AKR mice have a marked suppressive effect on spontaneous and mitogen-induced proliferation of young mouse splenocytes in vitro and suppress the development of humoral immune response in immunized recipients during syngeneic transfer in vivo. Some disturbances in erythron system in preleukemic AKR mice manifested in the accumulation of immature erythroid precursors which are suppressors of immunocompetent lymphocytes are suggested to be a pathogenetic link in the development of leukemia.