Effects on interferon of heavy metal excess and zinc deficiency.

Near toxic concentrations of cadmium sulfate, mercuric chloride, and nickel sulfate reduced interferon action in tissue cultures, but increased intake by the intact mouse of lead acetate and mercuric chloride did not reduce interferon action. Lead and nickel given orally inhibited the protective activity of Newcastle disease virus against encephalomyocarditis virus-induced mortality, whereas cadmium, mercury, cobalt sulfate, and sodium arsenite given orally and deficiency of zinc did not influence this action. Excess lead and cobalt and deficiency of zinc, but not excess cadmium, mercury, or nickel, inhibited the protective activity of poly I/poly C against encephalomyocarditis virus-induced mortality. These results illustrate the various actions of increased concentrations of certain metals or a deficiency of zinc on interferon action or on actions of interferon inducers.