Nitric oxide levels and lipid peroxidation in plasma of patients with gastric cancer

Background: The aim was to investigate the levels of malondialdehyde and total NO2- Plus NO3- marker for NO. generation in gastric carcinoma and to correlate their levels with the cancer stage. Method: The pretreatment plasma samples were obtained from 38 patients with gastric cancer (seven patients at stage II, 19 at stage III and 12 at stage IV). Nitrite (NO2-) and nitrate (NO3-) levels, the end products of nitric oxide (NO.), were determined in these samples. NO2- was measured by using the Griess reaction and after enzymatic conversion of NO3- into NO2- by nitrate reductase, the resultant NO2- was also measured by the same method. Malondialdehyde (MDA), a lipid peroxidation marker, was measured by the thiobarbituric acid method. Results: The levels of plasma MDA, NO. and NO3- were significantly higher in patients with gastric cancer compared with the healthy control group. Higher levels of MDA, NO. and NO3- were observed as the stage of the disease increased. Conclusion: We found that increased NO. production and MDA levels were present in plasma of patients with gastric cancer. These increases can be associated with the oxidant-antioxidant status in these patients.