Elastin turnover in murine lung after repeated ozone exposure

Several lines of evidence suggest that ozone (O₃) may affect the connective tissue elements of the lung. Since alterations in the elastic properties of lung parenchyma have been implicated in two major forms of lung pathology, fibrosis and emphysema, lung elastin turnover was examined in mice repeatedly exposed to O₃. Swiss-Webster (ice were injected with l-[¹⁴C]lysine to radiochemically label the cross-linking amino acids (desmosines) of elastin. Three weeks later, they were exposed to either 1.5 ppm O₃ or filtered air for 4 days. Mice were then exposed every 8 weeks for a total of three exposures. Although a physical separation of the elastic fibers was noted in the more edematous areas of the O₃ exposed lung, lung elastin turnover, as measured by the change in radioactivity of the desmosines, was not significantly altered.