HELICOBACTER-PYLORI INFECTION ENHANCES N-METHYL-N-NITROSOUREA-INDUCEDSTOMACH CARCINOGENESIS IN THE MONGOLIAN GERBIL

No previous report has demonstrated the relationship between Helicobac ter pylori (HP) infection and gastric carcinogenesis in an experimenta l animal model, A total of 170 male Mongolian gerbils (MGs) were divid ed into nine groups (18 less than or equal to n less than or equal to 20 for each group). MGs of four groups were inoculated with HP before or after continuous N-methyl-N-nitrosourea (MNU) administration via th e drinking water. Both intestinal-type and diffuse-type adenocarcinoma s, including signet ring-cell carcinomas, were found at 40 weeks after the study commenced, but only in the HP inoculation groups with MNU e xposure and not in the MNU alone or HP inoculation alone control group s. The present findings demonstrate that HP infection increases the in cidence of MNU-induced adenocarcinoma of the glandular stomach in MGs.