幽门螺杆菌过氧化氢酶预防大鼠溃疡性结肠炎的实验研究

目的研究幽门螺杆菌过氧化氢酶对大鼠溃疡性结肠炎的预防作用。方法应用葡聚糖硫酸钠（dextran sulfate sodium,DSS）制备SD大鼠溃疡性结肠炎（UC）模型,将大鼠随机分为正常对照组、模型（DSS）组、幽门螺杆菌过氧化氢酶（Hp-CAT）预防组,观察大鼠一般症状,病理学方法检查大鼠肠黏膜改变,RT-PCR方法检测大鼠肠粘膜内TNF-α、IL-1β、IL-8mRNA的表达。结果DSS组最早出现腹泻及肉眼血便,CAT预防组较晚仅出现不同程度腹泻,正常对照组无改变。大体病理学及组织病理学见CAT预防组病理改变明显轻于DSS组,正常对照组无改变。DSS组和CAT预防组TNF-α、IL-1β、IL-8的表达水平均较正常对照组明显增高（P〈0.01）,CAT预防组的表达较DSS组却明显降低（P〈0.05）。结论幽门螺杆菌过氧化氢酶能够减轻大鼠溃疡性结肠炎的临床症状及肠道病理学改变,其机制与降低肠黏膜炎性因子表达有关。

Protective Effect of Helicobacter pylori Catalase on Ulcerative Colitis of Rats

Objective To study the protective effective of Helicobacter pylori catalase （Hp-CAT） on ulcerative colitis of rats. Methods Dextran sulfate sodium （DSS） induced ulcerative colitis （UC） models of SD rats was constructed. The ulcerative colitis rats were randomly divided into three groups： normal control group, DSS group and Hp-CAT group. Common symptoms and the mucosal pathology of the rats were observed. The expression levels of TNF-ot, IL-13 and IL-8 mRNA in their intestinal mucous membrane were determined by RT-PCR. Results Diarrhea and blood stool were first observed in DSS group, while only different levels of diarrhea were appeared later in Hp-CAT group and no changes in normal control group. The macro-pathological and histopathological changes in Hp-CAT group were less obvious than in DSS group, while there was no change in normal control group. Additionally, DSS group and Hp-CAT group had conspicuously higher expression levels of TNF-α, IL-1β, and IL-8 than normal control group （P〈0.01）, but expression levels in Hp-CAT group were significandy lower than those in DSS group （P〈0.05）. Conclusion Hp-CAT can relieve the clinical symptoms and pathological changes in intestinal tract of rats with UC, and the mechanism may be related to the lowering of the expression levels of inflammatory factors in intestinal mucosa.