The effects of quartz dust on lipid peroxidation, extracellular release of lactate dehydrogenase and nitroblue tetrazolium reduction in vitro pulmonary alveolar macrophages and polymorphonuclear leukocytes were examined. As controls, either macrophages alone or those exposed to inert corundum dust were used. An increase in malonyldialdehyde, a product of the decomposition of unsaturated fatty acids, was observed after alveolar macrophages had been incubated for 1hr with 3mg/107 cells quartz. A significant extracellular release of lactate dehydrogenase into the medium caused by quartz dust indicates that the quartz exerts damaging effects on macrophage membranes. Quartz considerably accelerated NBT reduction, whereas corundum did not cause any reduction.
The above studies thus indicate that lipid peroxidation induced by quartz particle ingestion in alveolar macrophages can be associated with the generation of superoxide anions which exert damaging effects on the cell membrane.