维生素C对幽门螺杆菌感染蒙古沙鼠胃上皮的保护效应

目的通过建立幽门螺杆菌(H.pylori)感染蒙古沙鼠的动物模型,观察H.pylori及H.pylori与N-甲基-N'-硝基-N-亚甲基胍(MNNG)联用作用后胃黏膜的组织学改变,并观察了维生素C的预防作用.方法160只SPF级蒙古沙鼠随机分为5组,每组32只.A组单用Hpylori菌液灌胃;B组在接种H.pylori后4周,摄入MNNG水(20μg/mL),连续30周;C组单用MNNG水(20μg/mL),连续30周;D组在B组基础上同时摄入加维生素C的食料;E组为空白对照组.各组分别在实验后12、36、48、52周各处死8只,取胃黏膜行组织学检查,用Warthin-starry银染、PCR和快速尿素酶法检测H.pylori.结果累计至52周肠化生和异型增生的发生率A组(87.5%,62.5%)、B组(78.1%,56.3%)显著高于C组(6.2%,6.3%)、D组(15.6%,9.4%)和E组(0%,0%),P＜0.01.B组的H.pylori感染率从接种后12周的100%下降到52周的66.7%.结论H.pylori感染与胃癌发生有关,维生素C在预防肠化生和异型增生的癌前病变上有一定作用.

Protective effect of vitamin C on gatric carcinogenesis in mongolian gerbils infected with Helicobacter pylori

Objective] Using a model of H.pylori infected Mongolian gerbil to observe the effect of H.pylori and N-methy-N'-nitro-N-nitrosoguanidine(MNNG) on gastric mucosa, and clarify the potential role of vitamin C in the prevention of gastric carcinoma. Methods] A total of 160 Mongolian gerbils, six-week-old ,were randomly divided into five groups (each 32 animals): Group A infected with H.pylori, Group B infected with H.pylori followed by MNNG administration; Group Creceived MNNG without H.pylori infection; Group D infected with H.pylori followed by administration of MNNG and vitamin C; Group E as control. Eight animals from each group were killed at 12, 24, 36, 48 weeks, and histopathological changes in their stomach were examined for chronic gastritis , intestinal metaplasia, atypical hyperplasia and adenoma. Result] The incidences of intestinal metaplasia and dysplasia in group A and B were significantly higher than those in the other groups (P<0.01).The incidences of H.pylori infection decreased from 100% at 12 weeks to 66.7% at 52 weeks in group B. Conclusion] H.pylori infection is related with gastric carcinogenesis, and vitamin C may prevent the development of gastric carcinoma.