Korean J Asthma Allergy Clin Immunol.  2005 Jun;25(2):117-122.

Effects of Diesel Exhaust Particles on Airway Inflammation and Hyperresponsiveness in a Murine Model

Abstract

BACKGROUND
Epidemiologic studies show that increases in diesel exhaust particles (DEP) can aggravate acute asthma. However, there were a few asthma models in mice exposed to DEP. Nitric oxide (NO) may contribute to airway inflammation and hyperresponsiveness (AHR).
OBJECTIVE
We have determined the effects of DEP on AHR and inflammation using a mouse model. We have also investigated the effects of DEP on the production of NO in vivo and in vitro. METHOD: The mice were intra-nasally sensitized with 0.6 mg/mL of DEP for 5 days and were challenged with 6 mg/m3 of DEP by inhalation route for 3 days. The mice were subjected to whole-body plethysmography and killed for performance of bronchoalveolar lavage and histology. Murine macrophage cell line, Raw 264.7 cells were exposed to 50microgram/mL of DEP and nitrate levels in the culture supernatants were measured with the Griess reagent. Expression of NO synthase was detected by RT-PCR. RESULT: DEP induced a significant increase in methacholine- induced AHR. The levels of IL-4 and eotaxin increased in the BAL fluid in mice exposed to DEP. DEP stimulated nitrite production in the BAL fluid. Nitrite increased in Raw 264.7 cells exposed to DEP. DEP stimulated the expression of iNOS in lung tissue in mice exposed to DEP. Alveolar macrophage was expressed iNOS mRNA 24 h and 48 h after stimulation with DEP in vitro with peak time in 48 h post- stimulation. CONCLUSION: It is suggested that DEP may induce AHR and produce NO, and that NO may be an important role in airway inflammation by DEP.

MeSH Terms

Air Pollution
Animals
Asthma
Bronchoalveolar Lavage
Cell Line
Inflammation*
Inhalation
Interleukin-4
Lung
Macrophages
Macrophages, Alveolar
Mice
Nitric Oxide
Nitric Oxide Synthase
Plethysmography
RNA, Messenger
Vehicle Emissions*
Interleukin-4
Nitric Oxide
Nitric Oxide Synthase
RNA, Messenger
Vehicle Emissions