盐酸氨溴索对脂多糖诱导急性肺损伤大鼠肺血管重塑的改善作用及机制

Improvement effect and mechanism of ambroxol hydrochloride on pulmonary vascular remodeling induced by lipopolysaccharide in rats with acute lung injury

目的 探讨盐酸氨溴索对脂多糖(LPS)诱导急性肺损伤(ALI)大鼠肺血管重塑的作用及机制。方法 选取80只SD大鼠,按照随机数字表法分为正常组、模型组、实验(盐酸氨溴索处理ALI)组、阳性[阳性对照药地塞米松(DXMS)处理]组各20只。除正常组外,其余组采用LPS构建ALI大鼠模型。术后第2天起每日分别在实验组和阳性组皮下注射1 ml、规格为20 mg/kg的盐酸氨溴索和DXMS,连续给药28 d,正常组和模型组每日注射等量生理盐水,连续注射28 d。实验流程结束后,采用苏木素-伊红(HE)染色检测病理组织,弹力纤维(EVG)染色检测血管重塑情况,TUNEL染色检测肺动脉平滑肌细胞凋亡情况,免疫组化染色检测α-平滑肌肌动蛋白(SMA)和血管内皮生长因子(VEGF)表达,线粒体膜电位试剂盒(JC-1)检测线粒体膜电位。结果 模型组肺小动脉中膜厚度大于正常组,血管肌化程度、肺动脉平滑肌细胞凋亡率高于正常组,肺组织中α-SMA、VEGF、线粒体膜电位、胱天蛋白酶(Caspase)-3、B细胞淋巴瘤(Bcl)-2相关X蛋白(Bax)表达高于正常组,Bcl-2表达低于正常组,差异均具有统计学意义(均P<0.05);实验组和阳性组肺小动脉中膜厚度小于模型组,血管肌化程度、肺动脉平滑肌细胞凋亡率低于模型组,肺组织中α-SMA和VEGF、线粒体膜电位、Caspase-3、Bax蛋白表达低于模型组,Bcl-2蛋白表达高于模型组,差异均具有统计学意义(P<0.05)。结论 肺平滑肌细胞可通过盐酸氨溴索降低凋亡率并对其血管重塑有改善作用,进而减少ALI肺组织损伤。

Objective To investigate the effect and mechanism of ambroxol hydrochloride on pulmonary vascular remodeling induced by lipopolysaccharide(LPS)in rats with acute lung injury(ALI).Methods Eighty SD rats were randomly divided into normal group,model group,experimental(ALI treated with ambroxol hydrochloride)group and positive〔positive control drug treated with dexamethasone(DXMS)〕group,with 20 rats in each group.Except for the normal group,the ALI rat model was established by LPS in the other groups.From the second day after operation,1 ml and 20 mg/kg of ambroxol hydrochloride and DXMS were subcutaneously injected into the experimental group and positive group for 28 d,and the normal group and model group were injected with the same amount of normal saline every day for 28 d.At the end of the experiment,pathological tissue was detected by hematoxylin-eosin(HE)staining,vascular remodeling was detected by elastic fiber(EVG)staining,apoptosis of pulmonary artery smooth muscle cells were detected by TUNEL staining,expressions ofα-smooth muscle actin(SMA)and vascular endothelial growth factor(VEGF)were detected by immunohistochemical staining,and mitochondrial membrane potential was detected by mitochondrial membrane potential kit(JC-1).Results The thickness of pulmonary arterioles in the model group was larger than that in the normal group,the degree of vascular myalization and the apoptosis rate of pulmonary artery smooth muscle cells in the model group were higher than those in the normal group,the expressions ofα-SMA,VEGF,mitochondrial membrane potential,Caspase-3 and B-cell lymphoma(Bcl)-2 related X protein(Bax)in the lung tissue of the model group were higher than those in the normal group,while the expression of Bcl-2 in the model group was lower than that in the normal group,the differences were statistically significant(all P<0.05).In the experimental group and positive group,the thickness of pulmonary arterioles media was smaller than that in the model group,the degree of vascular myalization and the apoptosis rate of pulmonary artery smooth muscle cells were lower than those in the model group,and the expressions ofα-SMA and VEGF,mitochondrial membrane potential,Caspase-3 and Bax protein in the lung tissue were lower than those in the model group,the expression of Bcl-2 protein was higher than that in the model group,the differences were statistically significant(P<0.05).Conclusions Pulmonary smooth muscle cells could reduce the apoptosis rate and improve the vascular remodeling through ambroxol hydrochloride,and then reduce the lung tissue injury in ALI.