HELICOBACTER-PYLORI LIPOPOLYSACCHARIDE INDUCES GASTRIC EPITHELIAL-CELLS APOPTOSIS

H.pylori is recognized as a primary etiologic factor in the pathogenes is of gastric disease. Here, we assessed the effect of intragastric ad ministration of H. pylori lipopolysaccharide at 50 and 200 mu g dose o n the epithelial cell apoptosis. Histological examination of the mucos al tissue two days following the treatment revealed that lipopolysacch aride at both doses induced in the rat stomach mucosal inflammatory re sponses typical of gastritis. The in situ DNA fragmentation assay demo nstrated that these changes were associated with a marked increase in gastric epithelial cell apoptosis. The apoptotic index in the controls averaged 0.3%, and increased dramatically to 59% with the lipopolysac charide at 50 mu g dose, while at the 200 mu g dose the apoptotic inde x of 71.9% was attained. The results point towards cell wall lipopolys accharide as a virulence factor responsible for the induction of gastr ic epithelial cell apoptosis by H. pylori.