Abstract
Airborne particulate matter (PM) is hypothesized to play a role in increases in asthma prevalence, although a causal relationship has yet to be established. To investigate the effects of real-world PM exposure on airway reactivity (AHR) and bronchoalveolar lavage (BAL) cellularity, we exposed naive mice to a single dose (0.5 mg/mouse) of ambient PM, coal fly ash, or diesel PM. We found that ambient PM exposure induced increases in AHR and BAL cellularity, whereas diesel PM induced significant increases in BAL cellularity, but not AHR. On the other hand, coal fly ash exposure did not elicit significant changes in either of these parameters. We further examined ambient PM-induced temporal changes in AHR, BAL cells, and lung cytokine levels over a 2-wk period. Ambient PM-induced AHR was sustained over 7 d. The increase in AHR was preceded by dramatic increases in BAL eosinophils, whereas a decline in AHR was associated with increases in macrophages. A Th2 cytokine pattern (IL-5, IL-13, eotaxin) was observed early on with a shift toward a Th1 pattern (IFN-γ). In additional studies, we found that the active component(s) of ambient PM are not water-soluble and that ambient PM-induced AHR and inflammation are dose-dependent. We conclude that ambient PM can induce asthmalike parameters in naive mice, suggesting that PM exposure may be an important factor in increases in asthma prevalence.
Original language | English (US) |
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Pages (from-to) | 1438-1443 |
Number of pages | 6 |
Journal | American journal of respiratory and critical care medicine |
Volume | 164 |
Issue number | 8 I |
DOIs | |
State | Published - Oct 15 2001 |
Keywords
- Air pollution
- Allergy
- Asthma
- Inflammation
ASJC Scopus subject areas
- Pulmonary and Respiratory Medicine
- Critical Care and Intensive Care Medicine