The Effect Of Helicobacter Pylori On Cell Apoptosis, Proliferation And Expression Of Cyclooxygenase-2 In Gastric Mucosa Of The Balb/c Mice

Objective To infect Balb/c mice by Helicobacter pylori(H,pylori)and observe the influence of Helicobacter pylori(H,pylori)NCTC11637 on growth of gastric mucosa cells of the Balb/c mice in the initial stage.We detected the expression of cyclooxygenase-2(COX-2)in gastric mucosa of the Balb/c mice,explored the influence of H.pylori on the cell apoptosis, proliferation and revealed the pathogenic mechanism of the H.pylori.Method We devided 40 Balb/c mice into 4 groups.Each group has 10 mice.The Groupl as the control group were given liquid media orally while Group2,3,4 were inoculated with H.pylori suspension(1.0×10~9CFU/ml).Every mouse will be given 0.3ml/d in 5 days. Group1,2,3,4 were sacrificed by turns after 10d,10d,24d,32d since the last inoculating.Do the following experiments.(1)The infection of H.pylori in gastric mucosa was analyzed by use of rapid urease test,Warthin-Starry silver staining and H.pylori culture.(2)COX-2 was detected by immunohistochemical analysis.(3)Analyse DNA ploid and Calculate the Proliferation Index(PI)by flow cytometry.Result(1)According to the diagnostic criteria of H.pylori infection:Control group are all H.pylori negative.The Group 2,3,4 have 10,9,8 mice which are H.pylori positive.As the time goes,the infection rate decreases.(2)The COX-2 expression has a increasing tendency,as time goes.There are statistically differences between Group1 and Group 2,3,4 and between Group2 and Group3,4(P＜0.01).But there is no statistically difference between Group3 and Group4 (P＞0.05).(3)FCM of the apoptosis indicate:The apoptosis rate have a increasing tendency, as time goes.There are statistically differences between all the groups(P＜0.01).(4)FCM of the PI indicate:The PI have a increasing tendency,as time goes.PI were statistically different between the groups(P＜0.01)except the Group 1 and 2(P＞0.05)Conclusion We can conclude that at the initial stage of the H.pylori infection,the gastric mucosa cells have a high COX-2 expression.The experiment also gives us a result that the apoptosis rate and the PI also have a increasing tendency.They have a significant correlation. The high COX-2 expression and the changes of cell kinetics induced by the H.pylori infection may have a relation with the pathogenic mechanism and the diversity of clinical manifestation after the H.pylori infection.