Inhibition of gastric mucosal laminin receptor by Helicobacter pylori lipopolysaccharide: effect of ebrotidine.

The effect of lipopolysaccharide from H. pylori, a bacteria implicated in the etiology of gastric disease, on the gastric mucosal laminin-receptor interaction was investigated. The receptor protein, prepared from rat gastric epithelial cell membrane by affinity chromatography on laminin-coupled Sepharose, was radioiodinated, and incorporated into liposomes which exhibited specific affinity towards laminin-coated surface. The binding was inhibited by H. pylori lipopolysaccharide, which caused a maximum inhibition of 96% at 50 micrograms/ml. The inhibitory effect of the lipopolysaccharide was prevented by an antiulcer agent, ebrotidine that evoked essentially complete restoration in binding at 6-8 micrograms/ml. The results demonstrate that H. pylori through its lipopolysaccharide interferes with gastric epithelial cell-laminin binding, and that this disruptive effect could be successfully countered by ebrotidine.