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 NO(2)(-) plus NO(3)(-) 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 (NO(2)(-)) and nitrate (NO(3)(-)) levels, the end products of nitric oxide (NO(*)), were determined in these samples. NO(2)(-) was measured by using the Griess reaction and after enzymatic conversion of NO(3)(-) into NO(2)(-) by nitrate reductase, the resultant NO(2)(-) 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 NO(3)(-) were significantly higher in patients with gastric cancer compared with the healthy control group. Higher levels of MDA, NO(*) and NO(3)(-) 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.