Soluble metals of residual oil fly ash compromise host defense in rats.
Roberts-JR; Taylor-MD; Antonini-JM
Am J Respir Crit Care Med 2003 Apr; 167(7):A109
Residual oil fly ash (ROFA) contributes significantly to ambient air pollution and has been associated with increased pulmonary morbidity in susceptible populations. The objective was to examine mechanisms by which soluble metals in ROFA may increase susceptibility to infection. ROFA (Boston Edison, Everett, MA) was suspended in saline and further separated, retaining the soluble portion (R-Sol). Metals were removed from R-Sol by chelation (R-Chelex). At day 0, rats were intratracheally instilled (IT) with ROFA (2.0 mg/rat) or equivalent quantities of R-Sol, R-Chelex, or saline. At day 3, rats received an IT dose of 5xl0^5 Listeria monocytogenes. On days 6 and 8, bronchoalveolar lavage (BAL) was performed after euthanasia, and cytokine levels in BAL fluid and chemiluminescence (CL) and nitric oxide (NO) generation from BAL cells were measured. Significant increases in lL-10 and decreases in IL-2 were observed in the R-Sol group after infection. In addition, production of CL and NO in animals treated with R-Sol were significantly reduced after infection. Rats treated with R-Chelex were no different from saline control in the parameters measured. By day 8, all infected R-Sol rats expired due to the inability of the lungs to clear the bacteria. The increase in pulmonary morbidity induced by ROFA is likely due to soluble metals that caused reductions in antimicrobial reactive oxygen and nitrogen intermediates and alterations in immune response illustrated by differential cytokine production.
Metals; Pollutants; Pollution; Pulmonary-system-disorders; Lung-disease; Lung-disorders; Lung-irritants; Bacteria; Immune-reaction; Laboratory-animals; Animal-studies; Animals
Abstract; Conference/Symposia Proceedings
Work Environment and Workforce: Mixed Exposures
American Journal of Respiratory and Critical Care Medicine, 2003 International Conference, The American Thoracic Society, Seattle, WA, May 16-21, 2003