乳杆菌对溃疡性结肠炎大鼠肠黏膜的影响

Effect of Lactobacillus on colonic mucosa in rats with ulcerative colitis

目的:探讨乳杆菌(LA)对溃疡性结肠炎(UC)大鼠肠黏膜的影响及相关机制.方法:30只SD大鼠随机分为正常对照组、UC模型组、LA预防组,每组10只.采用葡聚糖硫酸钠制作UC大鼠模型;LA预防组在造模前7d给予LA灌肠,观察各组大鼠粪便性状及光学镜下大肠黏膜的改变.采用RT-PCR检测IL-1β,TNF-α和IL-8表达.结果:正常对照组粪便正常,黏膜腺体结构完整,无炎细胞浸润.UC模型组从最初出现腹泻,发展到肉眼血便,组织切片也证实了腺体破坏、炎细胞浸润、绒毛脱落等炎症损伤.LA预防组较UC模型组的炎症程度明显减轻,TNF-α,IL-1β和IL-8的mRNA表达显著低于UC模型组(P<0.05).结论:LA具有预防UC作用,其机制可能与下调TNF-α,IL-1β和IL-8的表达有关.

AIM： To observe the effect of Lactobacillus on colonic mucosa in rats with ulcerative colitis （UC） and its possible mechanism. METHODS： Thirty SD rats were randomly divided into 3 groups： normal control group, UC model group and Lactobacillus pre-treated group, 10 rats per group. UC model in rat was induced by dextran sulfate sodium. Lactobacillus pre-treated group were given a clyster containing Lacidophilus for 7 d before modeling. The changes in the properties of dejecta and colonic mucosa of rats were observed under a light microscope. The expressions of TNF-ct, IL-1β and IL-8 mRNA were detected by RTPCR. RESULTS： Control group＇s feces were normal and glands structures were intact and no inflammatory cells invaded in colonic mucosa. The rats in UC model group appeared diarrhea originally and developed bloody dejecta that could be observed by naked eye, and the tissue section observation revealed that glands were destroyed, inflammatory cells invaded and flosses shed in colonic mucosa. Lactobacillus pre-treated group was lighter significantly than UC model group in the degree of inflammation of colonic mucosa. TNF-α, IL-1β and IL-8 mRNA expressions in Lactobacillus pre-treated group were significantly lower than those in UC model group（ P 〈 0.05 ）. CONCLUSION： Lactobacillus can prevent ulcerative colitis and the mechanism was possibly related to the down-regulated TNF-α, IL-1β and IL-8 expressions.