EXPERIMENTAL HELICOBACTER-PYLORI INFECTION INDUCES ANTRAL GASTRITIS AND GASTRIC MUCOSA-ASSOCIATED LYMPHOID-TISSUE IN GUINEA-PIGS

Humans infected with Helicobacter pylori have abnormally low levels of the antioxidant vitamin C, which protects against the formation of ca rcinogenic nitrosamines, in gastric juice, Guinea pigs, like humans an d nonhuman primates, have a dietary requirement for vitamin C, As such , these species have gastrointestinal vitamin C transport systems not found in other animals. We have developed and characterized a guinea p ig model of chronic gastric H., pylori infection with the rodent-adapt ed Sydney strain of H., pylori, At 4 weeks postinfection, five of six animals of the infected group and zero of two animals of the control g roup were positive for H., pylori as determined by culture or PCR At 1 5 weeks, six of six animals of the infected group and zero of two anim als of the control group were positive. H., pylori-specific seroconver sion was observed among infected animals. There were no histologic abn ormalities in the gastric antra or fundi of control guinea pigs, In co ntrast, there was multifocal, mild to moderate lymphohistiocytic antra l gastritis and formation of antral lymphoid follicles in H., pylori-i nfected animals. The lesion distribution in the gastric antra parallel ed that observed in H., pylori-infected humans. The H., pylori-infecte d guinea pig should prove useful in modeling the interaction of helico bacter and vitamin C in gastric carcinogenesis.