葶苈大枣泻肺汤通过ACE2-Ang-(1-7)-Mas轴对心梗后心衰模型大鼠心室重构的影响

Effects of Tingli dazao xiefei decoction on ventricular remodeling in model rats with heart failure after myocardial infarction through ACE2-Ang-(1-7)-Mas axis

目的探讨经方葶苈大枣泻肺汤对心肌梗死后心力衰竭模型大鼠心室重构的作用机制。方法应用左冠状动脉前降支结扎术构建心肌梗死后心力衰竭大鼠模型,分8组:假手术组、模型组、A779组(1 mg/kg)、A779(1 mg/kg)+葶苈大枣泻肺汤等效剂量组(0.8 g/kg)、A779(1 mg/kg)+葶苈大枣泻肺汤高剂量组(1.6 g/kg)、葶苈大枣泻肺汤等效剂量组(0.8 g/kg)、葶苈大枣泻肺汤高剂量组(1.6 g/kg)和氯沙坦钾组(10 mg/kg),各组分别给予等体积蒸馏水或者相应的药物,灌胃4周。采用Masson染色法测定大鼠心肌组织中胶原纤维分布;采用碱水解法测定心肌组织羟脯氨酸(Hyp)含量;采用免疫组化法检测心肌组织中Ⅰ型胶原蛋白(COLⅠ)、Ⅲ型胶原蛋白(COLⅢ)的表达水平;采用酶联免疫吸附测定法检测大鼠血清中基质金属蛋白酶2(MMP-2)、MMP-9、金属蛋白酶组织抑制因子1(TIMP-1)、可溶性致瘤性抑制因子2(sST-2)等心肌纤维化相关指标;采用Western blot法检测心肌组织中血管紧张素转换酶2-血管紧张素-(1-7)-Mas[ACE2-Ang-(1-7)-Mas]轴相关蛋白的表达。结果与假手术组比较,模型组、A779组心肌细胞排列紊乱,胶原纤维沉积明显增多,心肌纤维化明显,Hyp含量和MMP-2、MMP-9、sST-2水平显著升高,COLⅠ、COLⅢ阳性表达显著增强,TIMP-1水平和ACE2、Ang-(1-7)、Mas蛋白表达水平显著降低(P<0.05)。与模型组比较,葶苈大枣泻肺汤等效剂量组和高剂量组上述指标均可得到不同程度的改善。与A779组比较,A779+葶苈大枣泻肺汤等效剂量组及A779+高剂量组心肌排列及胶原分布可一定程度地改善,Hyp含量和MMP-2、MMP-9水平降低,COLⅠ、COLⅢ阳性表达显著减少(P<0.05),但Ang-(1-7)和Mas蛋白表达水平未显著升高。结论葶苈大枣泻肺汤可通过提高ACE2-Ang-(1-7)-Mas轴蛋白的表达改善心肌梗死后心力衰竭模型大鼠的心室重构。

OBJECTIVE To explore the mechanism of Tingli dazao xiefei decoction on ventricular remodeling in model rats with heart failure after myocardial infarction.METHODS The rat model of heart failure after myocardial infarction was established by ligation of anterior descending branch of left coronary artery,which was divided into 8 groups:sham operation group,model group,A779 group(1 mg/kg),A779(1 mg/kg)+Tingli dazao xiefei decoction equivalent-dose group(0.8 g/kg),A779(1 mg/kg)+Tingli dazao xiefei decoction high-dose group(1.6 g/kg),Tingli dazao xiefei decoction equivalent-dose group(0.8 g/kg),Tingli dazao xiefei decoction high-dose group(1.6 g/kg)and losartan potassium group(10 mg/kg).Each group was given equal volume of distilled water or corresponding drugs intragastrically for 4 weeks.Masson staining was used to determine the distribution of collagen fibers in rat myocardium.The content of hydroxyproline(Hyp)in myocardium was determined by alkaline hydrolyzation.The expressions of type Ⅰ and Ⅲ collagen(COLⅠ,COLⅢ)in myocardium were detected by immunohisto-chemistry.Myocardial fibrosis-related indexes such as matrix metalloproteinase-2(MMP-2),MMP-9,tissue inhibitor of metalloproteinase-1(TIMP-1)and soluble suppression of tumorigenicity-2(sST-2)were detected by ELISA.The protein expressions of angiotensin converting enzyme 2-angiotensin-(1-7)-Mas[ACE2-Ang-(1-7)-Mas]axis were detected by Western blot.RESULTS Compared with sham operation group,myocardial cells in model group and A779 group were disordered,collagen fiber deposition was significantly increased and myocardial fibrosis was obvious;the Hyp content and MMP-2,MMP-9,sST-2 levels were increased,and COLⅠand COLⅢ positive expressions were significantly enhanced;TIMP-1 level,protein expressions of ACE2,Ang-(1-7)and Mas were significantly decreased(P<0.05).Compared with model group,above indexes of Tingli dazao xiefei decoction equivalent-dose and high-dose groups were improved to different extents.Compared with A779 group,A779+Tingli dazao xiefei decoction equivalent-dose and A779+high-dose groups could improve myocardial arrangement and collagen distribution,reduce the Hyp content and MMP-2,MMP-9 levels,reduce positive expressions of COLⅠ and COLⅢ(P<0.05),but couldn’t improve Ang-(1-7)and Mas protein expression.CONCLUSIONS Tingli dazao xiefei decoction can improve ventricular remodeling in myocardial failure model rats after myocardial infarction by improving the expression of ACE2-Ang-(1-7)-Mas axis proteins.