Effect of esomeprazole on gastric mucosal lesion and its mechanism In rats

AIM:To observe the protective effect of esome- prazole on gastric mucosa and its mechanism. METHODS:Before the model of gastric mu- cosal lesion was made by pure alcohol,esome- prazole(20 mg/kg)was intragastrically ad- ministered while Nω-nitro-L-arginine methyl ester(L-NAME,4 mg/kg)and L-arginine(250 mg/kg)were intravenously injected into the rats.Gastric mucosal blood flow(GMBF)was measured with laser Doppler flowmetry(LDF), while gastric mucosal and serum NO_2/NO_3 levels were examined by cadmium granula- tion reduction and colorimetric method.The changes of ulcer index and the severity of tissue necrosis and neutrophil infiltration were also observed. RESULTS:The ulcer index was significantly lower in the rats with esomeprazole pretreatment than that in the model rats(5.6±2.2 vs 25.3±2.4, P＜0.01),and the degree of tissue necrosis and neutrophil infiltration were also much milder(P＜0.01).Prior administration of L-NAME obvious- ly inhibited the protective effect of esomeprazole was on gastric mucosa,but the inhibition was alleviated by L-arginine.Esomeprazole increased GMBF and gastric mucosal or serum NO_2/NO_3 level which was suppressed by L-NAME.Esome- prazole had no marked effect on the secretion of gastric acid. CONCLUSION:Esomeprazole can protect gastric mucosa against alcohol-induced injury, which is mediated by nitric oxide.