INHIBITION OF GASTRIC-MUCOSAL MUCIN RECEPTOR BY HELICOBACTER-PYLORI LIPOPOLYSACCHARIDE - EFFECT OF SULGLYCOTIDE

1. A receptor for mucin was isolated from the solubilized gastric epit helial cell membrane by affinity chromatography on Sepharose-bound whe at germ agglutinin. 2. The receptor protein displayed a molecular weig ht of 97 kDa and exhibited specific affinity towards mucin-coated surf aces. The optimum for mucin binding occurred at 60-100 mu g/ml, while the values for the receptor were 2.0-3.1 mu g/ml. 3. The mucin binding to the receptor was susceptible to Helicobacter pylori lipopolysaccha ride which caused maximum inhibition of 91% at 30 mu/ml. This inhibito ry effect of the lipopolysaccharide was abolished by a gastroprotectiv e agent, sulglycotide. 4. The effect of sulglycotide was dose dependen t and at 50 mu g/ml produced a 94% restoration in receptor-mucin bindi ng. Furthermore, sulglycotide was also capable of enhancing (97%) the mucin binding to its receptor in the absence of the lipopolysaccharide . 5. The results demonstrate that H. pylori through its lipopolysaccha ride interferes in the interaction of mucin with gastric epithelial su rfaces and that a gastroprotective agent, sulglycotide, counteracts th is effect, and hence is capable of preventing the Loss of mucin coat c ontinuity occurring with H. pylori infection.