麝香通心滴丸通过促血管新生改善糖尿病合并心肌梗死大鼠心功能的作用机制研究

Mechanism of Shexiang Tongxin Dropping Pill in improving cardiac function in diabetic rat with myocardial infarction by promoting angiogenesis

[目的]从促进血管新生角度探究麝香通心滴丸对糖尿病合并心肌梗死大鼠心功能的保护效果和作用机制。[方法]通过腹腔注射链脲佐菌素(55 mg/kg)及冠状动脉左前降支结扎术建立糖尿病合并心肌梗死大鼠模型,随机将大鼠分为糖尿病合并心肌梗死组(MI组)、麝香通心滴组(STDP组)[20 mg/(kg·d)],并设立正常血糖假手术组(Sham组),每组6只。STDP组每日予药物灌胃,Sham组与MI组每日予同体积蒸馏水。观察大鼠体质量、空腹血糖变化,给药28 d后采用超声心动图检测心功能;病理检测采用苏木精-伊红(HE)与Masson染色观察心肌结构及纤维化病变情况;免疫荧光麦胚凝集素(WGA)染色测量心肌细胞面积;免疫组化法观察心肌血小板-内皮细胞黏附分子-1(CD31)表达情况并测定心肌毛细血管密度;Wes全自动蛋白质印迹定量分析法、蛋白免疫印迹法(Western blot)测定心脏组织中血管内皮生长因子(VEGF)、磷酸化血管内皮生长因子受体2(p-VEGFR2)、促血管生成素-1(Ang-1)、酪氨酸激酶受体-2(Tie-2)、内皮型一氧化氮合酶(eNOS)、诱导型一氧化氮合酶(iNOS)、磷酸化内皮型一氧化氮合酶(p-eNOS)的蛋白表达水平。[结果]糖尿病大鼠出现明显的多饮多食多尿现象,血糖显著升高;与Sham组比较,MI组大鼠的左心室射血分数和短轴缩短率比值明显降低,心脏微血管密度明显下降,并出现明显的心肌纤维化与心肌细胞肥大(P<0.01);同时心肌组织中VEGF、p-VEGFR2、Ang-1、Tie-2、eNOS、p-eNOS蛋白表达明显降低(P<0.01),iNOS表达水平显著增加(P<0.01)。与MI组相比,STDP组大鼠心肌纤维化和心肌细胞肥大明显改善,微血管密度增加,VEGF、p-VEGFR2、Ang-1、Tie-2、eNOS、p-eNOS的蛋白表达水平提高(P<0.01或P<0.05),iNOS蛋白表达降低(P<0.05),心功能明显改善。[结论]麝香通心滴丸可保护糖尿病合并心肌梗死大鼠心功能,其作用机制可能与促进血管新生、改善心肌微循环障碍有关。

[Objective]To explore the protective effect and mechanism of Shexiang Tongxin Dropping Pills on cardiac function in diabetic rats with myocardial infarction from the perspective of promoting angiogenesis.[Methods]Model of diabetic myocardial infarction was established by intraperitoneal injection of streptozotocin(55 mg/kg)and left anterior descending coronary artery ligation.The rats were randomly divided into diabetic myocardial infarction(MI)group and Shexiang Tongxin Dropping Pills(STDP)group[20 mg/(kg·d)],and a normolglycemic sham operation(Sham)group was established,with 6 rats in each group.Ratsin the STDP group were given Shexiang Tongxin Dropping Pill by gavage every day,while the remaining groups were given the same volume of distilled water.The changes of body weight and fasting blood glucose of rats were observed,and cardiac function was detected by echocardiography after 28 days.HE and Masson staining were used for pathological detection to observe myocardial structure and fibrotic lesions,immunofluorescence wheat Germ Agglutinin(WGA)staining wasusedto measure myocardial cell area.Immunohistochemistry was used to observe myocardial platelet-endothelial cell adhesion molecule-1(CD31)expression,and the myocardial capillary density was determined.The protein expression levels of VEGF,p-VEGFR2,Ang-1,Tie-2,eNOS,iNOS and p-eNOS in cardiac tissues were determined by Wes automatic Western blot quantitative analysis system.[Results]The diabetic rats showed significant polydipsia,polyphagia and polyuria,and significantly increased blood glucose.Compared with the Sham group,the rats in the MI group showed significantly lower ratios of left ventricular ejection fraction and short-axis shortening,significantly decreased cardiac microvascular density,and significant myocardial fibrosis and cardiomyocyte hypertrophy(P<0.01).Meanwhile,VEGF,p-VEGFR2,Ang-1,Tie-2,eNOS and p-eNOS protein expression were significantly decreased(P<0.01)and i NOS expression level was significantly increased(P<0.01).Compared with the MI group,myocardial fibrosis and cardiomyocyte hypertrophy were significantly improved,microvessel density was increased,protein expression levels of VEGF,p-VEGFR2,Ang-1,Tie-2,eNOS and p-e NOS were increased(P<0.01 or P<0.05),and iNOS protein expression was decreased(P<0.05)in the STDP group rats,and cardiac function was significantly improved.[Conclusion]Shexiang Tongxin Dropping Pills could improve the cardiac function of diabetic rats with myocardial infarction,which was associated with promoting angiogenesis and improving myocardial microcirculation disorders.