Empirical Study To Compare The Mechanisms Of Angiogenesis In Artherosclerosis And Ischemic Myocardium And To Perform The Medicine Interventions For Them

Part one:Establishment of the animal model with both artherosclerosis and acute myocardial infarction.Objective:To establish the animal model both with artherosclerosis and acute myocardial infarction by using the interventional methods of the high fat diet and the cardiac catheter.Methods:20 male New-Zealand rabbits were randomly divided into 2 groups.Group A was fed the 1.5%high cholesterol diet for 9 weeks;Group B was fed the full diet.At the end of the third week,coronary arteriography was performed at first.Then the microtubule was put into the distal end of left anterior descending branch(LAD).The obstructive glue was prepared by mixing giant molecule embolism agent with iodized oil,and it was pushed into the vessel through the microtubule to induce acute myocardial infarction.Results:Out of 20 animals,16 survived.Coronary artery imaging,dynamic state ECG changes, observation of the heart in general,pathology staining and electron microscopy were used to confirm that the method of catheterization could induce acute myocardial infarction.The infarction area was 28.32%±5.21%.The CD34 positive area and the density of angiogenesis in the marginal zone of infarction were significantly higher than that in the infarction or normal area (P＜0.05).Compared with group B,the cholesterol level of group A was significantly increased (P＜0.05).The endomembrane thickness and endomembrane/tunica media thickness ratio in group A were higher than those in group B.The positive areas of plaque in aortic arch were measured by SudanⅢstaining.The plaques of group A were significently increased as compared to group B(82.56±6.56%vs 4.25±0.98%,P＜0.01).Conclusion:We successfully established the animal model with both acute myocardial infarction and artherosclerosis.Part two:Comparison for mechanisms of angiogenesis in artherosclerosis and ischemic myocardiumObjective:To compare the differences of the angiogenesis mechanisms between artherosclerosis and ischemic myocardium in the animal model with both acute myocardial infarction and artherosclerosis. Methods:16 male New-Zealand rabbits were randomly divided into 2 groups.Group A was fed the full diet and was induced acute myocardial infarction by catheterization.Group B was fed the high cholesterol diet and was also induced acute myocardial infarction by catheterization.The CD34 positive response intensity of myocardium and aorta vessel wall,and the density of angiogenesis of myocardium were measured by immunohistochemical staining.The expressions of HIF-1α,VEGF and VEGFR2(Flk-1/KDR) were detected by real time fluorescent quantitation PCR and Western blot methods.Results:In the areas of the normal,the infarction and the marginal zone,the CD34 positive response intensity and the density of angiogenesis had significant difference(P＜0.01),the expression of HIF-1αalso had significant difference,those of the marginal zone of infarction were greater than the infarction area,which were greater than the normal area;the expressions of VEGF and VEGFR2 in the marginal zone were higher than that in other areas;the expressions of VEGF and VEGFR2 between the infraction area and the normal area showed no significant difference.In the aorta vessel walls of the full diet group(group A) and the high cholesterol diet(group B),the CD34 positive response intensity had significant differences(P＜0.01).The expressions of HIF-1α,VEGF and VEGFR2 also had significant difference with group B higher than group A.Conclusion:Angiogenesis was observed not only in artherosclerosis but also in ischemic myocardium.Part three:The empirical study-the animal model with both artherosclerosis and acute myocardial infarction was intervened with simvastatin.Objective:To investigate the effect of simvastatin on angiogenesis of artherosclerosis and ischemic myocardium by using the intervention of simvastatin on the animal model.Methods:20 male New-Zealand rabbits with artherosclerosis and acute myocardial infarction were randomly divided into 2 groups.Group A received simvastatin by intragastric administration; Group B received physiological saline by intragastric administration.The level of blood fat,the heart function and the positive areas of plaque were determined.The CD34 positive response intensity of the marginal zone of infarction and aorta vessel wall,as well as the density of angiogenesis of myocardium were measured by immunohistochemical staining.The expressions of HIF-1α,VEGF and VEGFR2 were detected by real time fluorescent quantitation PCR and Western blot methods.Results:The cholesterol level and the positive areas of plaque of simvastatin group were significantly decreased(simvastatin vs control,P＜0.01).The cardiac function was significantly increased(simvastatin vs cotrol,P＜0.01).In the marginal zone of infarction,the CD34 positive response intensity and the density of angiogenesis of simvastatin group were higher than that of the control group(P＜0.01);simvastatin significantly increased the expressions of HIF-1αand VEGFR2,but did not change the expression of VEGF.In the aorta vessel walls,the CD34 positive response intensity of simvastatin group was lower than that of control group(P＜0.01); simvastatin significantly decreased the expressions of HIF-1α,VEGF and VEGFR2.Conclusion:Simvastatin inhibited angiogenesis in the plaque,increased angiogenesis in the marginal zone of infarction,and improved cardiac function.Part four:The empirical study -the animal model with both artherosclerosis and acute myocardial infarction was intervened with integripetal rhodiola herb and Shexiang Baoxinwan.Objective:To investigate the effect of integripetal rhodiola herb and Shexiang Baoxinwan on angiogenesis of artherosclerosis and ischemic myocardium in the animal model.Methods:30 male New-Zealand rabbits with artherosclerosis and acute myocardial infarction were randomly divided into 3 groups equally.Group A received integripetal rhodiola herb by intragastric administration;Group B received Shexiang Baoxinwan;Group C received physiological saline.The level of blood fat,the heart function and the positive areas of plaque were determined.The CD34 positive response intensity of the marginal zone of infarction and aorta vessel wall,and the density of angiogenesis of myocardium were measured by immunohistochemical staining.The expressions of HIF-1α,VEGF and VEGFR2 were detected by real time fluorescent quantitation PCR and Western blot methods.Results:The cholesterol level of integripetal rhodiola herb group was higher than that of the control group and Shexiang Baoxinwan group(P＜0.01),but between the control and Shexiang Baoxinwan groups,there was no significant difference.Compared with the control group,the positive areas of plaque in the medicine intervention groups were significantly decreased(P＜0.01).The cardiac function of each group had significant differences at the end of experiment. The cardiac function of integripetal rhodiola herb group was greater than Shexiang Baoxinwan group,which was greater than the control group.In the marginal zone of infarction,the CD34 positive response intensity and the density of angiogenesis of each group had significant difference(P＜0.01),those of integripetal rhodiola herb group were greater than Shexiang Baoxinwan group,which were greater than the control group;integripetal rhodiola herb significantly increased the expressions of HIF-1α,VEGF and VEGFR2;Shexiang Baoxinwan also significantly increased the expressions of VEGF and VEGFR2,but did not change the expression of HIF-1α.In the aorta vessel walls,the CD34 positive response intensity of integripetal rhodiola herb group and Shexiang Baoxinwan group was lower than that of the control group(P＜0.01),but there was no significant difference between them;integripetal rhodiola herb and Shexiang Baoxinwan significantly decreased the expressions of HIF-1α,VEGF and VEGFR2.Conclusion:Integripetal rhodiola herb and Shexiang Baoxinwan increased angiogenesis in the marginal zone of infarction,improved cardiac function,and inhibited angiogenesis in the plaque. The effect of integripetal rhodiola herb was slightly better than Shexiang Baoxinwan.