Distribution of Helicobacter pylori in a Mongolian gerbil gastric ulcer model

Background and Purpose: To the authors' knowledge, histopathologic changes associated with early H. pylori infection and ulceration have not been esta blished. We examined presence of H. pylori infection in an acetic acid-indu ced gastric ulcer (AAU) model in Mongolian gerbils. Methods: Sixty Mongolian gerbils were used as an AAU model, and another 60 gerbils were studied as a control (non-AAU) group. All animals were orally administered A, pylori, then were evaluated by use of histologic and bacter iologic examinations. Results: Helicobacter pylori were scattered on the surface mucous gel layer and in the pyloric gland gastric were pits; inflammation seen at the early stages later extended to the mucosa of the fundic gland area. The organism s were predominantly observed in the AAU model, but findings were comparabl e to those in controls at 1, 3, 7, 14, 28, or 56 days. Evaluation with rega rd to viable bacterial numbers reflected the histologic aspects, that the p yloric gland area had more viable counts than did the fundic gland area. Ca rbohydrate composition of mucin differed between pyloric and fundic gland a reas. These findings shed light on L-fucose related to the H. pylori adhesi ve factor abundant in mucin of the pyloric gland area. Conclusions: Findings for this ulcer model of Helicobacter pylori infection make it useful for the study of onset of infection and screening of anti-u lcer agents.