Helicobacter pylori-induced carcinoids in glandular stomach of Mongolian gerbils

Objective: To investigate the roles of infection of Helicobacter pylori(Hp) and effects of Hp eradication in the development of gastric carcinoids in Mongolian gerbils. Methods: A total of 100 animals were divided into seven groups; A, B without Hp were sacrificed after 50 and 100 weeks as controls, Hp was inoculated into group C, D, E, F, G. Group F and G received eradication of Hp after 75 weeks and 50 weeks, respectively. Results: In control group A and B, no hyperplasia/dysplasia and carcinoids were observed. In Hp-infected groups (C, D, E,), Anti-Hp antibodies and serum gastrin levels significantly increased at 50 week, 75 weeks and 100 weeks, and the incidences of hyperplasia/dysplasia and carcinoids were 27.8% (5/18), 31.2% (5/16), 58.3% (14/24) and 16.7% (3/18), 31.2% (5/16), 62.5% (15/24), respectively, and significandy higher than each control group(P<0.01). The areas of carcinoids increased accordingly over the time(P<0.01). After eradication of Hp in group F at 75 weeks and in group G at 50 weeks, values for anli-Hp IgG titer, gastrin levels decreased gradually. The frequencies of hyperpla-sia/dysplasiaand and carcinoids were 25.0% (4/16), 15.4% (2/13) and 37.5% (6/16), 23.1% (3/13), respectively. The incidences of hyperplasia/dysplasia and carcinoids in earlier Hp-eradicated group G were significantly lower than non-eradicated group E(P<0.001). The areas of carcinoids also marked reduced compared with non-eradicated group E(P<0.001). There were significant correlations between anti-Hp antibodies and serum gastrin levels (P<0.005), and between serum gastrin levels and carcinoids (P<0.001). Conclusion: These results suggested that Hp infection plays a critical role in development of gastric carcinoids and eradication of Hp might be effective in preventing development of Hp-related gastric carcinoids in Mongolian gerbils.