OUTDOOR AIR PARTICULATE MATTER ENHANCE AIRWAY HYPERRESPONSIVENESS IN MURINE MODEL OF ASTHMA

Abstract

Introduction While previous epidemiologic studies have demonstrated that increase in air particulate matter (PM) concentration is associated with risk of asthma exacerbation, the mechanisms of PM induced asthma exacerbation are poorly understood. Methods PM was collected using high-volume air sampler in Incheon, Korea and was suspended in PBS. To induce the phenotype of asthma, BALB/c mice were sensitized with intraperitoneal administration of ovalubmin (OVA) and alum, and challenged with OVA with or without PM. Effect of PM administration during OVA challenge in OVA sensitized mice and na?ve mice were evaluated by measurement of airway hyperresponsiveness (AHR), inflammatory cell count in bronchoalveolar lavage (BAL) fluid, and lung histology. Results Treatment of PM with OVA in OVA sensitized mice showed significant increase in AHR without change in inflammatory cell count in BAL fluid or histology, compared to PM-nontreated mice with asthma. Enhanced AHR was accompanied by increased synthesis of TNF-α. Exposure to same dose of PM in na?ve mice did not induce significant change in AHR and airway inflammation. Conclusion These findings suggest that PM plays an important role in aggravation of asthma by enhancing AHR and increased production of TNF-α.