Superoxide dismutase and glutathione in the gastric mucosa of patients with chronic liver disease.

The total activity of superoxide dismutase and glutathione peroxidase and the tissue content of Cu,Zn-superoxide dismutase, glutathione, and lipoperoxides in the gastric mucosa were determined in patients with chronic liver disease and in healthy controls. The mean levels of Cu,Zn-superoxide dismutase in liver cirrhosis and in hepatocellular carcinoma with cirrhosis were significantly reduced compared to controls (32.0 +/- 4.4, and 35.8 +/- 2.2, vs 44.6 +/- 2.2 ng/mg protein, p < 0.01). Mucosal levels of glutathione were significantly lower in chronic active hepatitis, liver cirrhosis, and hepatocellular carcinoma with cirrhosis than in controls (9.7 +/- 2.1, 8.9 +/- 2.3, and 11.0 +/- 3.4, vs 23.6 +/- 4.7 nmol/mg protein, p < 0.05). However, there were no significant differences between chronic liver disease and controls in the activity of gastric superoxide dismutase and glutathione peroxidase. Gastric lipoperoxide concentrations were significantly higher in chronic active hepatitis, liver cirrhosis, and hepatocellular carcinoma with cirrhosis than in controls (0.56 +/- 0.07, 0.50 +/- 0.12, 0.50 +/- 0.05 vs 0.18 +/- 0.03 nmol/mg protein, p < 0.05). These results suggest that the concentrations of gastric mucosal antioxidants were decreased in chronic liver disease, and that these changes may be responsible for the higher frequency of gastric mucosal lesions observed in patients with chronic liver disease.