Role of nitric oxide in oxidative damage in isolated rabbit gastric cells exposed to hypoxia-reoxygenation.

The present study aimed to investigate the role of nitric oxide on the oxidative damage in isolated rabbit gastric cells exposed to hypoxia-reoxygenation. Nitric oxide synthesis modulators such as L-arginine and NG-nitro-L-arginine methyl ester, a nitric oxide donor, sodium nitroprusside, and superoxide dismutase were used to treat the cells, and the synthesis and secretion of mucus, lipid peroxide production, and glutathione contents of the cells were determined. As a result, hypoxia-reoxygenation decreased nitric oxide production and the synthesis and secretion of mucus, as well as glutathione contents of gastric cells, but hypoxia-reoxygenation increased lipid peroxide production. Pretreatment with L-arginine, a substrate for nitric oxide synthase, sodium nitroprusside, and superoxide dismutase prevented the increase in lipid peroxide production and the decreases in glutathione contents, as well as the synthesis and secretion of mucus induced by hypoxia-reoxygenation. However, NG-nitro-L-arginine methyl ester, a nitric oxide synthase inhibitor, had no effect on these alterations. In conclusion, nitric oxide has an antioxidant defensive role on gastric cells by maintaining mucus and glutathione.