Helicobacter pylori lipopolysaccharide inhibition of gastric mucosal somatostatin receptor.

A gastric mucosal somatostatin receptor was isolated from the solubilized epithelial cell membrane by affinity chromatography on a column consisting of covalently coupled [D-Tryp8]SRIF-14 to Affi-Gel 10. The receptor protein displayed a molecular weight of 61kDa and exhibited specific affinity towards 125I-labeled [Tyr11]SRIF-14 with the optimum range of 4-8 micrograms/ml. The binding of somatostatin to its mucosal receptor was inhibited by lipopolysaccharide from H. pylori. The inhibitory effect was proportional to the concentration of lipopolysaccharide up to 50 micrograms/ml and reached a maximum of 94.1% inhibition. The results suggest that H. pylori, through its lipopolysaccharide, is capable of interfering with somatostatin regulatory effect on gastric mucosal G-cell function.