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 NOgeneration 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 (NO 2 -) and nitrate (NO 3 -) 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. Malondialde- hyde (MDA), a lipid peroxidation marker, was measured by the thiobarbituric acid method. Results: The levels of plasma MDA, NOand NO 3 - were significantly higher in patients with gastric cancer compared with the healthy control group. Higher levels of MDA, NOand NO 3 - were observed as the stage of the disease increased. Conclusion: We found that increased NOproduction 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.