Acute exposure to diesel exhaust particles elicits dose-dependent pulmonary inflammatory and impairment of lung function in naive BALB/C mice

Aim: Diesel exhaust particles (DEP) produced from the combustion of diesel fuel are the major contributor to particulate pollution in urban areas. Previous studies show signifi cant impacts on lung function as a result of chronic DEP exposure; however, the effects of a single acute exposure in a healthy lung are unknown. This study aimed to examine the effects of a single instillation of DEP on pulmonary infl ammation and lung function and to determine the role sex and dose play in these responses.

Methods: Mice were intranasally inoculated with 10, 30 or 100 μg DEP. At predetermined time points, mice were euthanized and bronchoalveolar lavage taken for analysis of infl ammatory cells, cytokines and phagocytosis of DEP by alveolar macrophages. Lung function was measured 6 and 24 hours postinoculation with 100 μg DEP using the forced oscillation technique and plethysmography.

Results: The recruitment of infl ammatory cells (macrophages and neutrophils) was dose dependent and similar between male and female mice with the greatest response being measured in mice inoculated with 100 μg DEP. A single dose of 100 μg DEP was suffi cient to induce impairments in lung function at FRC, and the volume dependence of lung mechanics in female, but not male, mice.

Conclusions: We have shown that acute exposure to DEP elicits dose- and sex-dependent pulmonary infl ammation and impairment of lung function in naïve BALB/c mice.