| Expression of oxidant and antioxidant enzymes in human lung and interstitial lung diseases | ||
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CuZnSOD showed positive immunoreactivity in the bronchial epithelium of healthy controls. The localization and regulation CuZnSOD in the lungs of experimental animals have been relatively well elucidated (Coursin et al. 1992, Oberley et al. 1993, Clyde et 1993, Chang et al. 1995), and they may have similarities in human and animal lung. Our findings on healthy human lung are in agreement with previous studies on human lung showing positive CuZnSOD reactivity in the bronchial epithelium. CuZnSOD has been found especially in ciliated epithelial cells and Clara cells (Coursin et al. 1992, Coursin et al. 1996). CuZnSOD is not usually induced by cytokines (Tsan et al. 1992, Kinnula et al. 1995b) and these previous findings are also in agreement with our study, which shows relatively weak immunoreactivity of CuZnSOD both in the cells of BAL samples and alveolar macrophages and positive staining especially in the ciliated epithelium.
CuZnSOD showed positive immunoreactivity also in the bronchial epithelium of the patients of sarcoidosis and extrinsic allergic alveolitis, but no expression in the granulomas of either of these diseases. Also consistent with the constitutive nature of this enzyme, its expression was very similar in the control and diseased lung.