Abstract: Objective To explore the expression of trefoil factor family2(TFF2) in gastric mucosa during healing of experimental gastric ulcer of rats. Methods Acetic acidinduced ulcers were produced by injection acetic acid to submucosa of gastric anterior wall. The expressions of TFF2 peptide/mRNA in gastric ulcer group(GU,42 adult male rats), normal salinel group(NS,42 adult male rats,) and normal group(N,6 adult male rats) were detected by immunohistochemistry (IHC) and RT-PCR respectively. Results The results of IHC showed that the expression of TFF2 peptide in N group was weakly positive, and on the day 1 after acetic acid injection, TFF2 positive cells significantly increased,and reached the peak on the day 6TFF2 showed more stronger expression near muscularis mucosa,which mainly located in the cytoplasm of parietal cells. On the day 10 and 14 after acetic acid injection, the integral absorbance(IEM>A/EM>) values of TFF2 were lower than that on the day 6, but maintained a higher expression.On the day 23,the expression of TFF2 in GU group significantly decreased,but was more than that in the control groups(EM>P/EM><0.05 or EM>P/EM><0.01).The result of RTPCR showed that the change of TFF2 mRNA was consistent with TFF2 peptide,TFF2 mRNA showed more stronger expression on the day 4 and 6 in GU group. Conclusion TFF2 plays

Key words: Gastric ulcer, Trefoil factor family 2, Immunohistochemistry, RT-PCR, Rat