人参总次苷改善心肌梗死后心肌重构的作用机制

The Mechanism of Total Secondary Ginsenosides in Improving Myocardial Remodeling after Myocardial Infarction

目的:探讨人参总次苷(TSG)改善心肌梗死后大鼠心肌重构的作用机制。方法:结扎大鼠冠状动脉前降支建立心肌梗死模型,假手术组只穿线不结扎(等量蒸馏水灌胃)。造模成功后将大鼠随机分为模型组(等量蒸馏水灌胃)、低剂量组(灌胃人参总次苷11.65 mg/kg)、高剂量组(灌胃人参总次苷23.30 mg/kg)、氯沙坦组(灌胃氯沙坦10 mg/kg),每日1次,连续4周。采用超声心动图评估大鼠心脏功能;苏木精-伊红(HE)和Masson染色观察心肌组织损伤和纤维化;比色法检测心肌组织羟脯氨酸(HYP)含量;酶联免疫吸附法(ELISA)检测血清脑钠肽(BNP)、血管紧张素Ⅱ(AngⅡ)、乳酸脱氢酶(ALD)及心肌组织α-平滑肌肌动蛋白(α-SMA)、基质金属蛋白酶-9(MMP-9)、基质金属蛋白酶-2(MMP-2)含量;应用原位末端标记测定法(TUNEL)检测细胞凋亡;实时荧光定量聚合酶链式反应(RT-PCR)检测Bcl相关X蛋白(Bax)、B细胞淋巴瘤-2(Bcl-2)、半胱氨酸蛋白酶3(Caspase-3)、半胱氨酸蛋白酶8(Caspase-8)、半胱氨酸蛋白酶9(Caspase-9)mRNA表达;蛋白免疫印迹法(Western Blot)检测心肌组织Bax、Bcl-2、Caspase-3、Caspase-8、Caspase-9蛋白表达。结果:与假手术组比较,模型组心功能下降,BNP、AngⅡ、ALD表达增加;组织损伤及纤维化增加,心肌组织HYP、α-SMA、MMP-9、MMP-2表达上升;心肌细胞凋亡增加,Bax、Caspase-3、Caspase-8、Caspase-9 mRNA与蛋白表达增高,Bcl-2 mRNA与蛋白表下降,差异均有统计学意义(P<0.01)。与模型组比较,低剂量组、高剂量组、氯沙坦组心功能增强,BNP、AngⅡ、ALD表达减少;组织损伤及纤维化减轻,心肌组织HYP、α-SMA、MMP-9、MMP-2表达降低;心肌细胞凋亡减少,Bax、Caspase-3、Caspase-8、Caspase-9 mRNA与蛋白表达降低,Bcl-2 mRNA与蛋白表达升高,差异均有统计学意义(P<0.01)。结论:人参总次苷可增强心功能,减少细胞凋亡,减轻心肌损伤和纤维化,改善心肌重构。

Objective:To investigate the mechanism of total secondary ginsenosides(TSG)on myocardial remodeling after myocardial infarction.Methods:Myocardial infarction model was established in rats by ligation of anterior descending coronary artery,and the sham operation group was threaded without ligation(gavaged with equal volume of distilled water).After successful modelling,the rats were randomly divided into model group(gavaged with equal volume of distilled water),low-dose group(gavaged with total secondary ginsenosides 11.65 mg/kg),high-dose group(gavaged with total secondary ginsenosides 23.30 mg/kg)and losartan group(gavaged with losartan 10 mg/kg),once a day for 4 weeks.Echocardiography was used to evaluate the rat heart function.Hematoxylin-eosin(HE)and Masson staining were used to observe myocardial tissue injury and fibrosis.The content of hydroxyproline(HYP)in myocardial tissue was detected by colorimetry.The contents of brain natriuretic peptide(BNP),angiotensinⅡ(AngⅡ),lactate dehydrogenase(ALD)andα-smooth muscle actin(α-SMA),matrix metalloproteinase-9(MMP-9)and matrix metalloproteinase-2(MMP-2)in serum were detected by enzyme-linked immunosorbent assay(ELISA).Apoptosis was detected by in situ end labeling assay(TUNEL).Rea-l time fluorescence quantitative polymerase chain reaction(RT-PCR)was used to detect the mRNA expressions of BCL-related X protein(Bax),B-cell lymphoma-2(Bc-l 2),Caspase-3,Caspase-8 and Caspase-9.The protein expressions of Bax,Bc-l 2,Caspase-3,Caspase-8 and Caspase-9 were detected by Western Blot.Results:Compared with sham operation group,the cardiac function of model group decreased,and the expression of BNP,AngⅡand ALD increased,while the expressions of HYP,α-SMA,MMP-9 and MMP-2 in myocardial tissue increased,and the apoptosis of cardiomyocytes increased,the mRNA and protein expressions of Bax,Caspase-3,Caspase-8 and Caspase-9 increased,and the mRNA and protein surface of Bc-l 2 decreased,with statistical significance(P<0.01).Compared with the model group,the cardiac function was enhanced in the low-dose group,high-dose group and losartan group,the expression of BNP,AngⅡand ALD decreased,while the expressions of HYP,α-SMA,MMP-9 and MMP-2 in myocardial tissue decreased,and the apoptosis of cardiomyocytes decreased,the mRNA and protein expressions of Bax,Caspase-3,Caspase-8 and Caspase-9 decreased,and the mRNA and protein expressions of Bc-l 2 increased,with statistical significance(P<0.01).Conclusion:Total secondary ginsenosides could enhance cardiac function,reduce cell apoptosis,alleviate myocardial damage and fibrosis,and improve myocardial remodeling.