黄芪提取物对心肌梗死大鼠心肌组织中VEGF/Flt1/Flk1的表达分析

EXPRESSION ANALYSIS OF VEGF/FLT1/FLK1 ON MYOCARDIAL TISSUEIN RAT SUBJECTED TO MYOCARDIAL INFARCTION TREATED WITH ASTRAGALUS EXTRACT

目的研究黄芪提取物(Astragalus Extract,AE)对心肌梗死大鼠心肌组织中VEGF及其受体Flt1/Flk1的表达调控作用,探讨黄芪促血管新生作用机制,为心肌梗死的治疗提供理论和实验依据。方法通过结扎大鼠心脏的左冠状动脉前降支造成心肌梗死的模型,然后将大鼠分为模型组、AE低剂量组(10 mg·kg^(-1)·d^(-1))、中剂量组(20 mg·kg^(-1)·d^(-1))、高剂量组(40 mg·kg^(-1)·d^(-1)),另外再设假手术组,仅仅穿线而不结扎。各组大鼠数量为8只。各治疗组给予AE上述对应的各药物剂量灌胃(ig)给药,模型组及假手术常规饲养,饲养4周后,把大鼠处死。应用HE染色、Masson染色分析左心室心肌细胞组织形态学变化和血管结构病理成分变化;反转录PCR(RTPCR)法测定心肌组织中VEGF、Flt1、Flk1 mRNA的表达变化;免疫组化染色法和免疫印迹法分析心肌组织中血管内皮生长因子VEGF、Flt1、Flk1的蛋白表达变化。结果 HE染色分析,模型组大鼠心肌细胞坏死严重,成纤维细胞增生较多,并伴有炎性浸润;AE低、中剂量组大鼠,心肌细胞形态结构不清晰,排列不齐,炎性浸润略微;AE高剂量组的大鼠心肌细胞形态结构完整,有效降低成纤维细胞的增生。与模型组比较,AE各组大鼠心肌组织结构相对规整,胶原含量明显下降(P<0.05),新生的血管数量明显增(P<0.05),内皮细胞形态相对完整,VEGF及Flt1、Flk1 mRNA和蛋白表达水平显著升高(P<0.01)。结论 AE可明显改善大鼠心肌梗死后心肌组织的紊乱状态,促进受损心肌组织中新生血管数量的增加,提高受损心肌组织中VEGF、Flt1、Flk1 mRNA和蛋白的表达。

Objective Studies of Astragalus Extract( Astragalus Extract,AE) on myocardial infarction in rat myocardial tissue VEGF( vascular endothelial growth factor) and its receptor Flt1/Flk1 expression regulation function,discusses the root of remembranous milk vetch to promote angiogenesis mechanism,provide theoretical and experimental basis for the treatment of myocardial infarction. Methods: Through ligation ratheart left anterior descending coronary artery to cause myocardial infarction model,and then the rats were divided into model group,the AE low dose group( 10 mg·kg^(-1)·d^(-1)),middle dose group( 20 mg·kg^(-1)·d^(-1)) group,Gao Jiliang( 40 mg·kg^(-1)·d^(-1)),and sham operation group only thread without ligation the number of rats in each group was 8. The dose of each treatment group were given intragastric administration of the corresponding AE( g for the sweet potato,the model group and the sham conventional breeding,feeding 4 weeks later,the rats to be put to death Application of HE staining and Masson staining analysis of left ventricular myocardial tissue morphology and pathological vascular structures composition changes; Reverse transcription PCR( RT-PCR)method determination of VEGF in myocardial tissue,Flt1,Flk1 mRNA expression change; Immunohistochemical staining method and western blot method analysis the myocardial tissue of vascular endothelial growth factor VEGF、Flt1、Flk1 Protein Expression changes.Results: HE staining analysis,the model group rats myocardial cell necrosis,hyperplasia of fibroblasts,accompanied by inflammatory infiltration; AE is low,middle dose group of rats,the myocardial cell morphology is not clear,notneat,inflammatory infiltrates slightly;AE rat myocardial cell morphology of high dose group of complete,effectively reduce the proliferation of fibroblasts. Compared with model group,AE each rat myocardial tissue structure is relatively uniform,collagen content significantly decreased( P < 0. 05),the newborn blood vessels volume increased significantly( P < 0. 05),endothelial cells to form a relatively complete,VEGF and Flt1、Flk1 mRNA and protein expression were significantly increased( P < 0. 01). Conclusion: AE can obviously improve the disorder of myocardial tissue after myocardial infarction in rats and promote the increase of the number of new blood vessels in the damaged myocardial tissue and increase the expression of VEGF,Flt1,Flk1 mRNA and protein in the injured myocardium.