双羟基黄酮醇对心肌再灌注损伤中局部心肌血流量影响的实验研究

目的:评价双羟基黄酮醇对缺血后冠脉内皮功能的作用以及评价其对致死性心肌缺血再灌注损伤的防治效果。方法:测定意识清醒、无应激状态下绵羊的冠状血管对不同浓度静脉输注的乙酰胆碱的反应,闭塞冠状动脉1 h然后进行7 d的连续再灌注,再灌注的同时进行双羟基黄酮醇或vehicle的治疗,测定缺血状态下和再灌注开始后的血液动力学指数和局部心肌收缩力,评估冠脉血管对乙酰胆碱的反应,并心脏测量梗死面积。结果:(1)双羟基黄酮醇处理后可预防心率上升,显著降低左室舒张末压在再灌注过程中的升高幅度;(2)乙酰胆碱引起的浓度依赖性心率、心搏出量和外周血管传导力的上升并不受到双羟基黄酮醇的处理和心肌缺血/再灌注的影响;(3)双羟基黄酮醇处理后梗死面积显著缩小;(4)双羟基黄酮醇处理可以显著改善危险心肌边缘区域的局部心肌血流。结论:双羟基黄酮醇可显著缩小心肌梗死面积,延长缺血后心肌再灌注中可显著改善内皮功能,可显著减弱危险心肌边缘区局部血流量的进行性损伤。

Effects of 3', 4 '-dihydroxynavonol on regional myocardial blood flow during myocardial reperfusion injury

Objective To investigate the actions of 3', 4'-dihydroxyflavonol on postischaemic coronary endothelial function and on the progression of postischaemic "no reflow".Methods The coronary vascular responses to intravenous infusion of acetylcholine were determined in conscious unstressed sheep.With the completion of baseline measurements,1-hour coronary occlusion was followed by continuous reperfusion for 7 days,with vehicle or 3',4'-dihydroxyflavonol treatment at the time of reperfusion.Haemodynamic indices and regional myocardial contractility were recorded.Coronary vascular responses to ach were evaluated.The heart was excised to quantify infarct size and to collect myocardial tissues for regional myocardial blood flow measurement.Results(1)3',4'-dihydroxyflavonol treatment prevented the increase of heart rate,and significantly reduced the increase extent of left ventricular end diastolic pressure during reperfusion;(2)Acetylcholine caused concentration dependent increases of heart rate,cardiac output and total peripheral conductance that were not influenced by 3',4'-dihydroxyflavonol treatment and myocardial ischemia/reperfusion;(3)Infarct size expressed as a percentage of the area was dramatically smaller after 3',4'-dihydroxyflavonol treatment;(4)3',4'-dihydroxyflavonol treatment markedly improved regional myocardial blood flow in the border zone of myocardium at risk.Conclusion Bolus injection of 3',4'-dihydroxyflavonol upon reperfusion markedly reduces myocardial infarct area,significantly improves endothelial function during myocardial reperfusion following prolonged ischaemia,significantly attenuates the progressive impairment of regional blood flow to the border zone of myocardium at risk.