Omeprazole attenuates neutrophil-endothelial cell adhesive interaction induced by extracts of Helicobacter pylori

In this study, the influence of omeprazole on the adhesive activity of neutrophils, provided by an extract of Helicobacter pylori, was determined. Human neutrophils were collected from peripheral blood and labelled with a fluorochrome. Helicobacter pylori (NCTC 11637) was cultured and its water extract was obtained by centrifugation of the bacterial suspension. Neutrophils were incubated with the extract in a plastic plate. Percentage adherence was calculated by measuring the fluorescence of floating and adherent cells. Rat mesenteric venule was prepared on an intravital microscope and the number of neutrophils which adhered to venular endothelium was counted. Neutrophil adherence to the plastic plate was increased by the presence of H. pylori extract. Pretreatment with omeprazole significantly decreased this adherence in a dose-dependent manner (10(-6)-10(-4)mol/L). Neutrophil adherence to the mesenteric venule was also increased by H. pylori extract and significantly inhibited by omeprazole. These results indicate that the neutrophil-endothelial adhesive interaction is inhibited by omeprazole, suggesting that omeprazole prevents neutrophil recruitment to the gastric mucosa associated with H. pylori infection.