福氏志贺菌感染后大鼠肠功能紊乱模型建立以及肠道通透性变化和肠黏膜IL-1β表达

发布时间：2018-01-19 23:33

本文关键词： 感染肠功能紊乱动物模型内脏敏感性小肠通透性结肠通透性　出处：《安徽医科大学》2009年硕士论文　论文类型：学位论文

【摘要】： 背景和目的:肠易激综合征是最常见的功能性胃肠病,其病因和发病机制至今仍不明确。目前对该病的研究仍缺乏一个稳定易行,可靠可行的动物模型。此项研究的目的就是:建立福氏志贺菌感染后肠功能紊乱大鼠模型,在此基础上探讨肠功能紊乱大鼠肠道通透性的变化以及肠黏膜IL-1β的表达,为感染后肠易激综合征的病因和发病机制提供依据。方法:将40只雄性Wistar大鼠随机分为实验组和对照组,实验组用5*109cfu\ml 4型福氏志贺菌2ml灌胃,对照组大鼠予2ml生理盐水灌胃。于灌胃后每日观察大鼠大便的性状,并于第1天、第3天、第14天、第21天行大便培养,在感染后第21天、42天和63天给大鼠行直结肠球囊扩张观察其腹部回撤反射中引起大鼠腹部抬离桌面和弓背的最小容量阈值来反映感染后大鼠的内脏敏感性。感染后第68天用乳果糖、甘露醇和三氯蔗糖配置的溶液给大鼠灌胃,用气相色谱法检测大鼠灌过糖溶液后5小时尿中乳果糖和甘露醇的排泄率比值(L/M)及第6小时至24小时尿中三氯蔗糖的排泄量来分别反应小肠道通透性和结肠通透性的变化。上述实验全部结束后将所有大鼠处死,取末端回肠及近端结肠行组织病理学检查观察炎症情况并采用免疫组化S-P法检查肠黏膜IL-1β的表达。结果:(1)用4型福氏志贺菌感染后第1~2天大鼠出现稀便和粘液便,7~10天就基本恢复正常,在感染后第21天行内脏敏感性后大鼠再次出现大便变稀、不成形带粘液,有18只大鼠反复出现大便性状改变直到实验结束。对照组大鼠在整个实验期间大便一直正常。感染组大鼠在感染后第1天及第3天大便培养出致病菌,在第14天及第21天大便培养均为阴性。在感染后第21天、42天、63天测得引起大鼠腹部抬离桌面和弓背的最小容量阈值较对照组均明显减低(P0.05)。组织病理学检查未见有明显的中性粒细胞浸润及间质水肿。(2)采用气相色谱法测得感染后大鼠5小时尿中L/M值和第6小时至24小时尿中的三氯蔗糖的排泄量较对照组均明显增加(P0.05)。(3)感染后大鼠末端回肠及近端结肠黏膜IL-1β的表达较对照组均明显增加(P0.05)。结论:(1)福氏志贺菌感染后大鼠肠功能紊乱模型建立成功。(2)肠功能紊乱大鼠小肠通透性及结肠通透性明显增加,肠黏膜IL-1β表达增加,说明感染后肠功能紊乱大鼠存在肠黏膜屏障的破坏和肠黏膜的低度炎症。
[Abstract]:Background and objective: irritable bowel syndrome is the most common functional gastrointestinal disease, its etiology and pathogenesis are still unclear. A reliable and feasible animal model. The aim of this study was to establish a rat model of intestinal dysfunction after Shigella flexneri infection. On this basis, the changes of intestinal permeability and the expression of IL-1 尾 in intestinal mucosa in rats with intestinal dysfunction were studied. Methods: 40 male Wistar rats were randomly divided into experimental group and control group. The rats in the experimental group were given 2 ml of Shigella flexneri type 4 and the rats in the control group were given 2ml normal saline. The feces were observed daily and on the first day after the rats were fed with 5 pieces of 109cfu\ ml 4 Shigella flexneri. Feces were cultured on day 3, day 14 and day 21 after infection. 42 and 63 days of balloon dilatation of straight colon were performed in rats to observe the minimum volume threshold of abdominal withdrawal reflex to reflect the visceral sensitivity of infected rats. 68 days after infection, the minimum volume threshold of abdominal lift away from the tabletop and back of the bowels of rats was observed. With fructose. Rats were fed with mannitol and sucrose trichloride solution. The excretion rate ratio of lactofructose to mannitol in urine of rats was determined by gas chromatography after 5 hours of glucose solution administration. The excretion of sucrose in urine from 6 hours to 24 hours was used to reflect the changes of intestinal permeability and colon permeability respectively. All the rats were killed after all the above experiments were completed. The distal ileum and proximal colon were taken for histopathological examination to observe inflammation and immunohistochemical S-P method was used to detect the expression of IL-1 尾 in intestinal mucosa. The rats infected with Shigella flexneri type 4 showed dilute stool and mucus stool on the 1st day after infection. 10 days after infection, the rats returned to normal basically. After 21 days of infection with visceral sensitivity, the rats again appeared defecation thinning and anamorphic mucus. There were 18 rats repeatedly appeared the change of defecation until the end of the experiment. The control group rats had normal defecation during the whole experiment. The infected rats in the first and third day after infection feces culture pathogenic bacteria. Stool culture was negative on the 14th and 21st day and 42 days after infection. At 63 days, the minimum volume threshold of abdominal lift away from the table and back of the rat was significantly lower than that of the control group (P 0.05). No obvious neutrophil infiltration and interstitial edema were found in histopathological examination. 2) the values of L / M in 5 hours urine and the excretion of sucralose in urine from 6 hours to 24 hours after infection were significantly increased by gas chromatography compared with the control group. The expression of IL-1 尾 in the distal ileum and proximal colon of the infected rats was significantly higher than that in the control group (P 0.05). Conclusion the intestinal dysfunction model of rats infected with Shigella flexneri was successfully established. (. 2) intestinal permeability and colon permeability were significantly increased in rats with intestinal dysfunction. The increased expression of IL-1 尾 in intestinal mucosa showed that the intestinal mucosal barrier was destroyed and the intestinal mucosal inflammation occurred in the rats with intestinal dysfunction after infection.
【学位授予单位】：安徽医科大学
【学位级别】：硕士
【学位授予年份】：2009
【分类号】：R574;R-332

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