幽门螺杆菌感染对结直肠癌发生的相关因素分析

Impact of Helicobacter pyloriinfections on development of colorectal cancer

目的探讨幽门螺杆菌(Hp)感染对结直肠癌发生的相关因素,为预防结直肠癌发生提供依据。方法将选取的60只清洁级雄性Wistar幼年大鼠随机分为4组,第1组为单纯Hp组,用Hp菌灌胃法定植Hp;第2组单纯N-甲基亚硝基脲(MNU)组用Hp菌液等量布氏肉汤灌喂,10周后用MNU灌肠诱发结直肠癌形成;第3组采用Hp+MNU联合处理定植Hp基础上,10周后用MNU灌肠诱发结直肠癌形成;第4组用与Hp菌液等量布氏肉汤灌喂基础上用MNU等量去离子水经肛门灌肠,定期处死大鼠后提取标本,检测Hp,同时做病理切片标本,观察有无肠壁增厚、肠黏膜充血、水肿、糜烂、溃疡及结节发生。结果 Hp组及Hp+MNU组大鼠较MNU组、第4组胃黏膜明显偏薄,以胃窦部较为明显,且可见肠上皮化生;Hp组及Hp+MNU组共定植28只小鼠,尿素酶染色阳性21只,培养阳性17只,Giemsa染色阳性达23只,两项阳性大鼠共有25只,占总定指数89.3%。结论长期的Hp感染可能会增加大鼠结直肠癌对致癌剂的敏感性,促进结直肠癌病变形成,而血胃泌素在结直肠癌的发生过程中是诱导机制之一。

OBJECTIVE To investigate the impact of Helicobacter pylori （Hp） infections on development of colorectal cancer so as to provide basis for the prevention of colorectal cancer. METHODS A total of 60 clean male young Wistar rats were selected and were randomly divided into 4 groups, the first group was of the simple Hp group, Hp was colonized with Hp gavage method, the second group was of simple MNU group, which was fed with Hp fermentation liquid with Brucella broth, after 10 weeks the colorectal cancer was induced by MNU enema; the colonized Hp in the third group was treated by combining with Hp and MNU, after 10 weeks the colorectal cancer was induced by MNU enema; the fourth group was treated with Brucella broth equal to Hp fermentation liquid to perform the anal enema with deionized water equal to MNU. The rats were sacrificed regularly for the specimen extraction, the Hp was detected, at the same time the pathological sections were made. The incidence of the bowel wall thickening, mucosal hyperemia, edema, erosion, ulcer or nodules was observed. RESULTS The gastric mucosa was significantly thinner in the Hp group and Hp＋MNU group than in the MNU group and the fourth group, especially significant in the gastric antrum, epithelial peanut invisible in intestinal tract; totally 28 mice were colonized in the Hp group and the Hp＋MNU group, totally 20 rats were tested with urease staining positive, 17 rats cultured positive, 23 rats with Giemsa staining tested positive, totally 25 rats were with the two items tested positive, accounting for 89. 3%. CONCLUSION The chronic Hp infection may increase the susceptibility of rat colorectal cancer to carcinogenic agents and promote the development of coloreetal cancer lesion. The serum gastrin is one of the induction mechanisms of colorectal cancer.