丹参对“二次打击”急性肺损伤大鼠的保护作用

Effect of radix salviae militiorrhizae on acute lung injury caused by two hits in rats

目的探讨丹参注射液对"二次打击"急性肺损伤(ALI)大鼠的干预作用及可能的机制。方法Wister大鼠30只,随机分为正常对照组、模型组、丹参干预组。采用"二次打击"法复制大鼠急性肺损伤模型:以油酸(OA)0.2 ml/kg从尾静脉注入,4 h后,脂多糖(LPS) 2 mg/kg从另一尾静脉注入。显微镜下观察病理,测肺湿/干比重(W/D),测定支气管肺泡灌洗液(BALF)中蛋白含量及中性粒细胞比例,计算肺通透指数(LPI)以评价肺损伤程度。免疫组化法检测肺组织Fas,FasL蛋白表达,原位缺口末端标记法(TUNEL)检测肺组织细胞凋亡。结果"二次打击"法可成功复制出急性肺损伤大鼠模型。实验中丹参干预组大鼠肺组织大体及病理损伤程度均明显轻于模型组,同时W/D,及BALF中中性粒细胞比例,肺通透指数亦较模型组明显减轻。免疫组化结果显示模型组Fas,FasL的表达明显高于其余两组(P<0.01),TUNEL示模型组细胞凋亡指数明显高于其余两组(P<0.01)。Fas,FasL蛋白表达强度与凋亡指数呈正相关。结论丹参注射液对"二次打击"所致急性肺损伤有保护作用。其机制可能与Fas,FasL表达减少,抑制肺组织细胞凋亡有关。

Objective To investigate the effects of radix salviae militiorrhizae （RSM） on acute lung injury induced by ＂two hits＂ and to study its probable mechanism. Method Thirty Wister rats were randomly divided into three groups： namely normal control group, model group and RSM treatment group. The model was created by ＂two-hits＂ in which 0.2 ml/kg oleic acid was injected into tail vein first, and then 2 mg/kg lipopolysaccharide was administered four hours later. After model rats sacrificed, the pathological changes of lung were observed, and lung wet/dry weight ratio, protein content, and the ratio of neutrophiles in brochoalveolar lavage fluid （BALF） were calculated. In addition, the expression of Fas, FasL protein and apoptosis were evaluated by studies and TUNEL technique. Results The acute lung injury rat model was successfully induced by ＂two hits＂. The gross and micrographic injury of lung was milder in RSM treatment rats than in model rats. The W/D ratio, protein contents and the ratio of neutrophiles in BALF were also markedly reduced in comparison with model rats, while the expression of Fas and Fasl, and the apoptosis index in model rats were signiticandy increased compared with other two groups. Furthermore, it showed a positive correlation between the expression of Fas, FasL, and the number of cell with apoptosis. Conclusions RSM shows a protective effect on ALT rats caused by ＂two hits＂ likely reaulted from inhibiting the expressions of Fas and Fasl, which are associated with the cell apoptosis of lung tissue.