宣肺通腑方对内毒素致急性肺损伤大鼠肺组织TLR4蛋白及其mRNA表达的影响

Effects of "Xuanfei Tongfu Decoction" on TLR4 Protein and mRNA Expressions of Lung Tissues in Rats with Acute Lung Injury Caused by Lipopolysaccharide

目的:探讨宣肺通腑方对脂多糖(LPS)诱导的急性肺损伤(ALI)大鼠肺组织TLR4蛋白及其mRNA表达的影响。方法:将32只雄性Wistar大鼠随机分为正常组、模型组、地塞米松组、宣肺通腑方组,每组8只。尾静脉注射LPS 6 mg/kg制备大鼠ALI模型。宣肺通腑方组在造模前3 d,按7.56 g/kg予宣肺通腑方水煎液灌胃,1次/d;地塞米松组在造模前1 h按5 mg/kg腹腔注射地塞米松。造模后6 h麻醉取样,分别采用免疫组化法和实时荧光定量聚合酶链反应(PCR)检测TLR4蛋白及其mRNA的表达,并于光镜下观察大鼠肺组织病理变化。结果:与模型组相比,宣肺通腑方组TLR4蛋白及其mRNA的表达均明显降低(P<0.05,P<0.01)。病理学显示,模型组大鼠肺组织出现大片出血及坏死,宣肺通腑方组大鼠肺组织病理改变明显轻于模型对照组,肺细支气管偶见炎症改变,水肿较轻,炎性细胞渗出较少。与地塞米松组比较,两药物干预组无显著性差异。结论:宣肺通腑方能减轻内毒素所致ALI大鼠肺组织损伤,对肺损伤有保护作用,其机制可能与其能降低内毒素致ALI大鼠TLR4蛋白及其mRNA的表达有关。

Objective：To investigate the effects of ＂Xuanfei Tongfu Decoction＂ on toll-like receptor 4（TLR4） protein and mRNA expressions of lung tissues in rats with acute lung injury caused by lipopolysaccharide（LPS）.Methods：Thirty-two male Wistar rats were randomly divided into four groups：normal control group,model group,dexamethasone group and ＂Xuanfei Tongfu Decoction＂ group,with eight rats in each group.The acute lung injury（ALI） model rats were established by injecting LPS（6 mg/kg） into tail vein.The rats in ＂Xuanfei Tongfu Decoction＂ group were administered by ＂Xuanfei Tongfu Decoction＂（7.56 g/kg） 3 days before modeling once a day,and the rats in dexamethasone group were intraperitoneally injected with dexamethasone（5 mg/kg） 1 h before modeling.All the rats were sacrificed 6 h after modeling.The TLR4 protein and mRNA expressions were detected by immunohistochemistry and real-time fluorescent polymerase chain reaction（PCR）,and the histopathology of the lung injury was observed by light microscope.Results：Compared with the model group,the expressions of TLR4 protein and mRNA were obviously decreased in ＂Xuanfei Tongfu Decoction＂ group（P〈0.05,P〈0.01）.The light microscope observation indicated that there were large areas of pulmonary hemorrhage and necrosis in model group,while in ＂Xuanfei Tongfu Decoction＂ group,the pathological manifestations were lighter than model group：the lung bronchiole inflammation seldom existed,the edema was lighter,and the inflammatory cells leaked little.There was no significant difference between two drug intervention groups.Conclusion：＂Xuanfei Tongfu Decoction＂ can alleviate the lung tissue injury of ALI rats induced by LPS,and has protective effects on lung injury,and its mechanisms may have relationship with decreasing the expressions of TLR4 protein and mRNA of lung tissues.