Tissue superoxide dismutase (SOD) activity and immunohistochemical staining in acute appendicitis: correlation with degree of inflammation.

The mechanism of progression of appendicitis has not been clarified. We examined tissue superoxide dismutase (SOD) activity, thiobarbituric acid reactive substance (TBARS), and the localization of Cu, Zn-SOD in 56 inflamed appendices in relation to histopathological classification. There was a significant difference in SOD activity between catarrhal appendix and phlegmonous and gangrenous appendix (2.3 +/- 0.1 vs 5.0 +/- 0.2 and 4.6 +/- 0.6 units/mg protein, respectively P < 0.05). TBARS value was highest in gangrenous appendix, being significantly different from the levels in the other two types (0.47 +/- 0.04 vs 0.19 +/- 0.01 n mol/mg protein, in catarrhal and 0.20 +/- 0.02, in phlegmonous appendix P < 0.05). Positive staining for Cu, Zn-SOD was demonstrated in 64% of catarrhal appendices, 96% of phlegmonous appendices, and 75% of gangrenous appendices, and intense positive staining was recognized in 9%, 28%, and 40% of these appendices, respectively. These results indicated that active oxygen influences the degree of inflammation in phlegmonous and gangrenous appendicitis. Gangrenous appendicitis and the other two types of appendicitis seemed to be different entities.