英夫利昔、沙利度胺对大鼠实验性结肠炎的治疗作用及其机制研究

炎症性肠病（IBD）是一种病因尚未明确的非特异性肠道炎症性疾病，传统治疗方法疗程长．疗效欠佳，容易反复发作。目的：观察并比较英夫利昔、沙利度胺对TNBS灌肠诱发的大鼠结肠炎治疗效果．并初步探讨两者治疗IBD的作用机制。方法：46只Sprague-Dawley大鼠随机分成正常对照组（n=10）、结肠炎组（n=12）、英夫利昔组（n=12）、沙利度胺组（n=12），后三组给予TNBS／乙醇灌肠诱导大鼠结肠炎模型。造模后第1d，英夫利昔组、沙利度胺组分别给予英夫利昔腹腔注射5mg·kg-1．d～、沙利度胺管喂200mg．kg-．d～，连续7d后处死。行疾病活动指数（DAI）、大体形态损伤指数（CMDI）和组织损伤指数（TDI）评分；以Real．timePCR、蛋白质印迹法和免疫组化分别检测结肠组织TNF-d、VEGF、caspase-3mRNA和蛋白表达；TUNEL法检测结肠上皮细胞凋亡情况。结果：结肠炎组大鼠DAI、CMDI、TDI评分均显著高于正常对照组（P〈O．05），TNF-a、VEGF、caspase-3mRNA和蛋白表达显著升高（P〈O．05）．结肠上皮细胞凋亡显著增加；给予英夫利昔或沙利度胺治疗后，上述指标均显著改善（P〈0．05）。结论：本实验成功构建了TNBS大鼠结肠炎模型，英夫利昔、沙利度胺对大鼠结肠炎均有明显的治疗效果，两者通过抑制TNF-a VEGF、caspase-3的表达，对IBD免疫、血管生成、凋亡过程起调节作用。

Effects and Mechanism of Infliximab and Thalidomide on Experimental Colitis in Rats

Background: Inflammatory bowel disease(IBD) is a non-specific intestinal inflammation with unknown etiology,traditional therapy needs a long course of treatment with poor efficacy and high recurrence rate.Aims: To observe and compare the effects of infliximab and thalidomide on rat model of colitis induced by TNBS,and to study the possible mechanism for the treatment of IBD.Methods: Forty-six Sprague-Dawley rats were randomly divided into normal control group(n=10),colitis group(n=12),infliximab group(n=12) and thalidomide group(n=12).Rats in the last three groups were infused with TNBS/ethanol by enema for the induction of colitis,and from the first day after induction of colitis,rats in infliximab group and thalidomide group were given infliximab(5 mg·kg-1·d-1) by intraperitoneal injection and thalidomide(200 mg·kg-1·d-1) by gavage,respectively,for 7 days.All the rats were sacrificed,scores of disease active index(DAI),common morphous damage index(CMDI),tissue damage index(TDI) were evaluated.Expressions of TNF-α,VEGF,caspase-3 mRNA and protein were detected by Real-time PCR,Western blotting and immunohistochemistry,respectively;apoptosis of colonic epithelial cells was determined by TUNEL assay.Results: Compared with normal control group,DAI,CMDI,TDI scores in colitis group were significantly increased(P<0.05),and expressions of TNF-α,VEGF,caspase-3 mRNA and protein in colitis group were significantly higher than those in normal control group(P<0.05),and apoptosis of colonic epithelial cells was markedly increased.After treatment with infliximab or thalidomide,all the above-mentioned indices were significantly improved(P<0.05).Conclusions: TNBS colitis model in rats is successfully established,both infliximab and thalidomide can provide therapeutic effects on TNBS induced colitis in rats model,probably by regulating the process of immune response,angiogenesis and apoptosis through inhibiting the expressions of TNF-α,VEGF,caspase-3.