Early Pathologic Changes of Mouse Gastric Mucosa Infected with Helicobacter pylori

Kim, Myung Wook; Cho, Yong Kwan; Han, Sang Uk; Kim, Wook Hwan; Joo, Hee Jae; Lee, Wee Kyo

Abstract

BACKGROUND/AIMS: The aim of the present study was to infect mice with H. pylori and then, to evaluate the effects of the infection on the early pathologic changes of gastric mucosa.
METHODS
A mouse- adapted H. pylori strain (SS1) was inoculated into 23 C57BL/6 mice. Twelve uninfected mice were also included as controls. The animals were sacrificed 3 days, 4 weeks, 8 weeks and 16 weeks after being infected with SS1. Gastric tissue were taken for histology and urease test.
RESULTS
Colonization was detectable in the stomach of all infected animals up to 16 weeks, but not in the control group. The organisms were detected in the mucus layers of the gastric epithelium. In the mice sacrificed 3 days after infection, neutrophil infiltration was identified in submucosal layer and lamina propria. Infiltration of mononuclear cells and mucosal atrophy were observed in the gastric mucosa in the mice sacrificed 4 and 8 weeks after infection respectively. In the mice sacrificed 16 weeks after infection, glandular destruction with severe infiltration of mononuclear cells was developed in the gastric mucosa.
CONCLUSIONS
Acute gastritis occurred from early days after infection with SS1. From 4 weeks after infection, gastric mucosa showed the features of chronic gastritis, progressing to severe atrophy.