Oxidant production by control and inflammatory bronchoalveolar leukocyte populations treated with mineral dusts in vitro

Using a rat model we set out to determine whether exposure of bronchoal-veolar-derived leukocytes to pathogenic mineral dusts in vitro caused them to undergo an oxidative burst and release potentially harmful oxidants. Three different populations, obtained by bronchoalveolar lavage, were chosen: control cells, cells obtained following instillation of heat-killedCorynebacterium parvum into the lung, and cells obtained following instillation of quartz. None of the populations showed any evidence of superoxide anion or hydrogen peroxide production when treated in vitro with the pathogenic dusts quartz and chrysotile asbestos, or the inert particulate titanium dioxide. Zymosan caused modest release of superoxide anion with all three populations, indicating that a respiratory burst was being provoked, while PMA, a soluble inducer of leukocyte oxidative burst, caused large-scale production of both oxidants. Preopsonization of mineral dust in rat serum did not render them capable of provoking an oxidative burst from lung-derived leukocytes.