BACKGROUND： Sepsis has become the greatest threat to in-patients, with a mortality of over 25%.The dysfunction of gut barrier, especially the immunological barrier, plays an important role in the development of sepsis. This dysfunction occurs after surgery, but the magnitude of change does not differentiate patients with sepsis from those without sepsis. Increased intestinal permeability before surgery is of no value in predicating sepsis. The present study aimed to observe the changes of intestinal mucosal immunologic barrier in rat models of sepsis induced by cecal ligation and puncture.METHODS： Sixty Sprague-Dawley rats were randomly divided into a sepsis group （n=45） and a control group （n=15）. The rats in the sepsis group were subjected to cecal ligation and puncture （CLP）, whereas the rats in the control group underwent a sham operation. The ileac mucosa and segments were harvested 3, 6 and 12 hours after CLP, and blood samples were collected. Pathological changes, protein levels of defensin-5 （RD-5） and trefoil factor-3 （TFF3） mRNA, and lymphocytes apoptosis in the intestinal mucosa were determined. In an additional experiment, the gut-origin bacterial DNA in blood was detected.RESULTS： The intestinal mucosa showed marked injury with loss of ileal villi, desquamation of epithelium, detachment of lamina propria, hemorrhage and ulceration in the sepsis group. The expression of TFF3 mRNA and level of RD-5 protein were decreased and the apoptosis of mucosal lymphocyte increased （P〈0.05） in the sepsis group compared with the control group. Significant differences were observed in RD-5 and TFF3 mRNA 3 hours after CLP and they were progressively increased 6 and 12 hours after CLP in the sepsis group compared with the control group （P〈0.05, RD-5 F=11.76, TFF3 F=16.86 and apoptosis F=122.52）. In addition, the gut-origin bacterial DNA detected in plasma was positive in the sepsis group.CONCLUSION： The immunological function of the intestinal mucosa was impaired in septic rats
目的探讨脓毒症大鼠肠道肠三叶因子mRNA表达变化及乌司他丁对其的影响。方法60只SD大鼠随机分为对照组、脓毒症组、预处理组及治疗组（n=15）。后三组采用盲肠结扎穿孔术（cecal ligation and puncture，CLP）制作大鼠脓毒症模型。预处理组在CLP前2h经尾静脉注射UT125，000u/Kg，治疗组在CLP后2h经尾静脉注射UT150，000u／Kg。于模型建立后12h取回肠黏膜，观察其病理改变并以RT—PCR法检测TFF3mRNA的表达。结果TFF3mRNA在脓毒症组显著下降（P〈0．05），预处理组及治疗组较脓毒症组有明显升高（P〈0．05），预处理组较治疗组明显升高（P〈0．05）。结论脓毒症大鼠TFF，mRNA表达明显下降，乌司他丁可显著上调其表达，保护肠黏膜，预防用药较治疗给药可能更有意义。
