Abstract
We attempted to investigate the effect of air pollution on functions of neutrophils collected from Fisher rats exposed to diesel engine exhaust. Rats were exposed either to a high concentration of diesel exhaust (H-group) or to the diesel exhaust from which particles deprived through filters (non-dust; ND-group) for six months. The concentration of NO2 gas and diesel exhaust particles was 2.6 ppm and 7.8 mg/m3 in H-group, and 2.1 ppm and 0.02 mg/m3 in ND-group, respectively. Phagocytic activity of the neutrophils from H-group was depressed. In addition, phagocytic activity of the neutrophils was further depressed in the ND-group. Neutrophil chemotaxis under agarose toward FMLP was decreased in either H-group or in ND-group, as compared with that of the control group.
These findings suggest that the inhalation of NO2 may impair the peripheral blood neutrophil functions such as phagocytosis and chemotaxis. The preservation of the neutrophil phagocytic activity in H-group as compared with ND-group seems to be partly due to the modulation of the stimulated alveolar macrophage function by diesel particles ingestion, which may finally potentiate the neutrophil function. And the toxic gas elements of the inhaled exhaust may be easily absorbed into blood by reaching the higher concentration of gas to pulmonary alveolar regions, which leads to the deterioration of neutrophil phagocytic activity in ND-group.
