Abstract: AIM: To investigate the protective effect of antiulcer agents omeprazole, misoprostol and Talcid on the acute gastric mucosa lesion.METHODS: Water immersion-restraint stress model were performed with SD rats.Mucosa lesion was evaluated by ulcer index.Apoptosis cells in gastric mucosa were measured by terminal deoxynucleatidyl transferase mediared dUTpnick and labelling(TUNEL) techniques, while expression of inducible NO synthase (iNOS) was detected by immunohistochemical staining and CX43 by In situ hyberdization.RESULTS: Compared with control group, the groups of pretreatment with Omeprazole, Misoprostol and Talcid showed a significant reduction of damaged mucosa and epithelial cell apoptosis, the effects of Omeprazole and Misoprostol were better than Talcid.Three antiulcer agents decreased iNOS expression and increased CX43 expression,the effect of Misoprostol and Talcid was better than Omeprazole.CONCLUSION: Omeprazole, misoprostol and Talcid can exert the protective effect to counter the acute gastric mucosa lesion with different mechanism.

Key words: stress, mucosal injury, apoptosis, inducible NO synthase, CX43, omeprazole, Talcid, misoprostol