Altered gastrin regulation in mice infected with Helicobacter felis

Altered gastrin expression associated with Helicobacter pylori infection ma y contribute to the pathogenesis of peptic ulcer disease or gastric cancer in man, but gastrin has not been investigated in a murine model of Helicoba cter infection. C57BL/6 mice were inoculated with Helicobacter felis and ex amined after 4-21 weeks for G and D cell numbers, antral gastrin and somato statin mRNA, and luminal pH. In H. felis-infected mice, gastrin mRNA declin ed at our and six weeks after infection to 57% and 23%, respectively, of un infected control values. Concurrently, somatostatin mRNA showed no change a t four weeks and a modest 25% decrease at six weeks after infection. Simila r reductions were noted in G and D cell numbers, resulting in a decrease in the G/D cell ratio after mice were infected with H. felis. Infected animal s also showed a loss of parietal and chief cells, and an increased gastric pH. H. felis infection in C57BL/6 mice leads to an early suppression of G c ell number and gastrin mRNA. These changes precede an alteration in somatos tatin cell number and mRNA and, coupled with reductions in parietal and chi ef cells, may contribute both to severe impairment of gastric acid output a nd the potential for carcinogenic processes.