Role of Oxygen Radicals in Acute Gastric Mucosal Injury Induced by Taurocholate-Serotonin in Rats

The objective of the present study was to investigate the role of oxygen radicals in the acute gastric mucosal injury induced by taurocholate combined with serotonin (TCA-5HT) in rats. Just after taurocholate had been given intragastrically at a dose of 30mM/rat, serotonin was injected subcutaneously at a dose of 20mg/kg. Superficial hemorrhagic erosions were observed on the glandular stomach 2h after administration of TCA-5HT. The level of lipid peroxides and that of α-tocopherol in the gastric mucosa significantly increased and decreased, respectively, with time after TCA-5HT treatment. Myeloperoxidase (MPO) activity, an index of neutrophil infiltration, in the gastric mucosa also increased significantly. Pretreatment with the combination of recombinant human Cu, Zn-superoxide dismutase (hSOD) and catalase significantly inhibited the gastric mucosal injury, accumulation of lipid peroxides, and the decrease in α-tocopherol content in the gastric mucosa. Polaprezinc, a new synthetic antioxidant, significantly inhibited gastric mucosal injury and the accumulation of lipid peroxides in the gastric mucosa. All these results suggest that oxygen radicals and lipid peroxidation are involved in the pathogenesis of the acute gastric mucosal injury induced by TCA-5HT.