EVIDENCE THAT EXPOSURE OF PARTICULATE AIR-POLLUTANTS TO HUMAN AND RATALVEOLAR MACROPHAGES LEADS TO DIFFERENTIAL OXIDATIVE RESPONSE

Macrophages and inflammatory cells generate active oxygen species in t he process of killing and degrading microorganisms. Air pollutant part icles may be ingested by macrophages and stimulate the same mechanisms to produce a long term oxidative burden to the lung if particles are not degraded. In the present study human and rat alveolar macrophages (AM) were compared in their response to inhaled particles using lumino l dependent chemiluminescence (CL) and peroxide dependent CL assays. C ytotoxicity was measured by the release of lactate dehydrogenase (LDH) activity in the supernatant. Human AM produced more oxidants than rat AM whether, unstimulated, after addition of particles or addition of particles then peroxidase. Human AM also had a different spectrum of r esponse to the same particles. Our results suggest that human macropha ges produce more reactive oxygen species in respond to particles than rat AM. (C) 1997 Academic Press.