Quantitative changes in glycosaminoglycans in the lungs of rats exposed todiesel exhaust

Exposure to diesel exhaust (DE) induces lesions in lung epithelium by gener ation of reactive oxygen species. Glycosaminoglycans (GAG), components of e xtracellar matrix, are thought to play important roles in cell proliferatio n and differentiation in the repair process of injured tissue. We investiga ted how GAG are related to the recovery of lung tissue from injury. Using h igh-performance liquid chromatography analysis, we deter-mined the amounts of GAG, such as chondroitin sulfate (CS), dermatan sulfate (IDS), and hyalu ronan (HA) in the lungs of rats exposed to DE for 4 weeks at concentrations of 0.3 or 3 mg/m(3) as suspended particulate matter, or to filtered air. T he contents of CS and HA in the surroundings of the bronchi were significan tly increased after exposure to DE. In addition, immunohistochemical staini ng showed that the number of 8-hydroxydeoxyguanosine-positive cells as a ma rker of cell damage, and proliferating cell nuclear antigen-positive cells also increased in the same areas in which the levels of GAG were elevated i n the lungs of rats exposed to 3 mg/m(3) DE. These results suggest that CS and HA in the lung contribute to cell proliferation and remodeling in the p rocess of recovery from injury caused by exposure to DE. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.