Pathological changes in glandular stomach of Helicobacter pylori-infected Mongolian gerbil model.

We have established a Helicobacter pylori-infected Mongolian gerbil model, following Hirayama's method, to clarify gastric diseases associated with H. pylori infection. We administered the culture broth of H. pylori ATCC 43504 orally to 8-week-old male Mongolian gerbils. After H. pylori inoculation, the gerbils were fed in a vinyl isolator. Subsequently, over the course of 48 weeks, they were killed for histopathological examination, H. pylori culture, and serum antibody measurement. H. pylori colonization in the glandular stomach was seen in all the infected gerbils, but only a few H. pylori were detected histologically. The serum antibody titer in the H. pylori-inoculated group increased gradually in comparison with controls. Acute inflammation, immature epithelium, and erosion were observed 2 weeks after H. pylori infection. Chronic inflammation was noted from 4 weeks after H. pylori infection. We also found intestinal metaplasia and gastric ulcers from 12 and 24 weeks after inoculation, respectively. Some histological findings were similar to those in humans, but the chronic inflammation in the gerbils was present mainly in the deep mucosa and submucosa. This appears to be a good animal model for H. pylori-associated gastric diseases and it may be useful for investigating the pathogenesis of H. pylori infection.