Helicobacter pylori-induced chronic active gastritis, intestinal metaplasia, and gastric ulcer in Mongolian gerbils

The establishment of persisting Helicobacter pylori infection in laboratory animals has been difficult, but in 1996 Hirayama reported the development of a successful Mongolian gerbil model. The present study was undertaken wi th two aims: to better characterize the normal histological structure and h istochemical properties of the gastric mucosa of the Mongolian gerbil; and to evaluate the progression of the histopathological features of H. pylori- induced gastritis in this animal model for one year after the experimental infection. Seventy-five Mongolian gerbils were used. Mongolian gerbils were sacrificed at 2, 4, 8, 12, 26, 38, and 52 weeks after H. pylori inoculatio n. Sections prepared from stomachs Immediately fixed in Carnoy's solution w ere stained with hematoxylin and eosin and Alcian blue at pH 2.5/periodic a cid-Schiff, a dual staining consisting of the galactose oxidase-cold thioni n Schiff reaction and paradoxical Concanavalin A staining, and with immunos taining for H. pylori and BrdU, H, pylori infection induced in the Mongolia n gerbil a chronic active gastritis, in which a marked mucosal infiltration of neutrophils on a background of chronic inflammation became detectable 4 weeks after Inoculation and continued up to 52 weeks. Intestinal metaplasi a and gastric ulcers appeared after 26 weeks in some of the animals, wherea s others developed multiple hyperplastic polyps. The Mongolian gerbil repre sents a novel and useful model for the study of H. pylori-induced chronic a ctive gastritis and may lend itself to the investigation of the epithelial alterations that lead to intestinal metaplasia and gastric neoplasia.