Effects of mineral dust on generation of superoxide radicals and hydrogen peroxide by alveolar macrophages, granulocytes and monocytes

Phagocytosis of quartz dust by alveolar macrophages and monocytes of rabbits and human monocytes and granulocytes is accompanied by stimulation of substrateless recovery of nitroblue tetrazolium to formazan. It reflects activation of oxygen-dependent bactericidal phagocyte system and generation of active oxygen forms. Less fibrogenic and cytotoxic dust of aluminium oxide increased formazan formation insignificantly. Extracellular generation of superoxide radicals and hydrogen peroxide was not discovered during phagocytosis of quartz by alveolar macrophages and monocytes. Incubation of human granulocytes with silica caused, on contrary, considerable increase in exogenous generation of superoxide radicals and hydrogen peroxide. Less fibrogenic dust of aluminium oxide under the conditions had no effect on generation of hydrogen peroxide and induced acute decrease in generation of superoxide radicals by granulocytes. The obtained results testify both to the essential part of active oxygen form during pathologic processes with pneumoconiosis, and also to a great similarity among biochemical processes, characterizing interaction of alveolar macrophages and monocytes with mineral dust.