Diesel particles induce nitric oxide production in murine alveolar macrophages and rat airways

The acute adverse health effects among respiratory and cardiovascular patie nts have been associated with particulate air pollution, containing diesel particles (DP). The mechanisms of these effects are unknown, but they may i nvolve inflammation. We investigated the effects of DP (30-3000 mu g/10(6) cells) on cell viability and production of nitric oxide (NO), interleukin-l (IL-1), interleukin-6 (IL-6), interferon-gamma OFN-gamma) and tumor necros is factor-cl (TNF-alpha) in murine RAW 264.7 macrophage cultures in vitro. DP caused a dose- and time-dependent NO-production and was cytotoxic in mur ine RAW 264.7 macrophages. Cytotoxicity preceded the increases in NO produc tion. DP had minimal effects on cytokine production. A single intratracheal instillation of DP 1 and 5 mg/rat increased NO produ ction and protein concentration in bronchoalveolar lavage fluid, and caused pulmonary edema and hemorrhage. The present results indicate that DP can induce both NO production and cyto toxicity in the lower respiratory tract, which may contribute to the short- term adverse respiratory effects of these particles. (C) 1999 Elsevier Scie nce B.V. All rights reserved.