IMMUNOELECTRON MICROSCOPIC LOCALIZATION OF COPPER-ZINC SUPEROXIDE-DISMUTASE IN HUMAN GASTRIC-MUCOSA

Superoxide radicals appear to play important roles in the pathogenesis of various gastric mucosal lesions. To add to a greater understanding of the pathogenesis of the various gastric mucosal lesions caused by oxygen-derived free radicals. we examined the distribution of copper-z inc superoxide dismutase (Cu,Zn-SOD) in normal human gastric mucosa us ing a direct immunoperoxidase method under light and electron microsco py. Under light microscopy. we detected Cu,Zn-SOD in propria gland cel ls but not in foveolar cells of the fundic mucosa or in antral gland c ells. With electron microscopy, Cu,Zn-SOD was detected in the ultrastr uctural morphology of parietal and chief cells. In parietal cells, it was present mainly in the cytoplasm. partially on the outer membrane o f mitochondria. and in the nuclei, and in chief cells, in the cytoplas m. Our findings suggest that Cu,Zn-SOD plays important roles in scaven ging oxygen radicals generated in the cytoplasm.