1993 Volume 28 Issue 4 Pages 220-230
Inflammation, increase in vascular permeability and mucous hypersecretion are the important pathological findings in chronic obstructive lung diseases such as asthma and chronic bronchitis. In the present experiment, vascular perm eability and bronchial inflammation were found to be mediated by superoxide (O2-) produced by diesel exhaust particles (DEP), because the pretreatment of mice with intratracheal injection of PEG-SOD (polyethylene glycol conjugated SOD) caused a decrease of endothelial damage, lung edema and mortality by pulmonary edema, and inflammation of the bronchial wall was also reduced by the pretreatment with PEG-SOD. The mucous hypersecretion was demonstrated as an increased content of bound-form sialic acid in bronchoalveolar lavage fluids and a proliferation of goblet cells on the bronchioles, which contain a large amount of mucous in the cytoplasm, and were stained in magenta by PAS-staining. Furthermore, infiltrations of eosinophils, neutrophils, lymphocytes and mast cells were observed under the submucosal layer by repeated instillations of DEP.
These findings suggest that O2- may play an important role in inducing of increase in vascular permeability, bronchiolar inflammation and mucous hypersecretion, and that DEP may be involved in the pathogenesis of lung diseases, including asthma and chronic bronchitis.
