Establishment of an animal model for chronic gastritis with Helicobacter pylori: potential model for long-term observations.

OBJECTIVES: To assess the suitability of an established experimental model for chronic gastritis associated with Helicobacter pylori for use in long-term observations. DESIGN: In a 3-year follow-up study of acute gastritis induced by H. pylori using an established experimental model with Japanese monkeys, we compared H. pylori-infected animals (n = 6) with a non-infected control group (n = 7). Colonization by H. pylori, gastritis scores, volume of intracellular periodic acid-Schiff-positive substances and the height of antral glands were investigated every 3 months for 3 years and compared with those of a control group. RESULTS: In the infected group, persistent colonization with H. pylori was demonstrated by culture and histological examinations. Gastritis scores were significantly higher than those of the control group, and the histological findings were quite similar to those of chronic active gastritis observed in humans. Simultaneously, significant decreases in the contents of periodic acid-Schiff-positive substances and in the height of antral glands were also demonstrated in infected animals. CONCLUSION: In Japanese monkeys, persistent colonization with H. pylori caused chronic gastritis quite similar to that observed in humans, thus providing a suitable animal model for evaluating the long-term prognosis of H. pylori infection.