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.