核黄素对离体大鼠心肌再灌注损伤时冠脉内皮的影响

目的　观察离体大鼠心肌缺血再灌注时冠脉内皮变化及核黄素 (riboflavin ,RBF)对其影响 ,并探讨其作用机制。方法　取 30只SD大鼠 ,2 5 0～ 30 0g ,随机分成 3组 ,即正常对照组 (NC组 ,n =10 )、缺血再灌注组 (I/R组 ,n=10 )、核黄素预处理组 (RBF预处理组 ,n =10 ) ,采用Langendorff离体心脏灌流装置 ,通过降低灌流量后复灌造成心脏I/R模型 ,测定缺血前、缺血后和再灌各个时段冠脉流出液中vWF、NO水平及CPF ,实验结束后取心肌组织测定NOS、SOD活性和MDA含量。结果　RBF预处理组与I/R组比较 ,冠脉流出液中NO含量显著增加 (P <0 .0 1) ,vWF含量降低 (P <0 .0 1) ,CPF明显升高 (P <0 .0 1) ,同时 ,心肌中TNOS、eNOS、SOD活性升高 (P <0 .0 1) ,MDA含量下降 (P <0 .0 1)。结论　RBF可以减轻离体大鼠心肌缺血再灌注损伤 ,其机制可能与其保护冠脉内皮免于受损及NO介导的冠脉扩张效应 ,改善低灌注状态 ,增强心肌抗氧化能力有关。

Effects of riboflavin on ischemic coronary endothelium over reperfusion injury in isolated perfused rat heart

ObjectiveTo investigate functional changes of coronary artery endothelium on ischemia/reperfusion of isolated perfused rat hearts and effects of riboflavin.Methods30 male SD rats,weighing 250～300 g,were randomly divided into three groups: normal control group(NC,n=6),ischemia/reperfusion group (I/R,n=6) riboflavin preconditioning group(RBF, n=6).In the ischemia/reperfusion model of isolated perfused rat hearts,the content NO and vWF in coronary effluent and CPF were measured in regular session and NOS?SOD activity and MDA content in myocardial tissue were measured when the experiment was over.ResultsIn the RBF group,the content of vWF in coronary effluent were lower than that in I/R group (P<0.01),but NO and CPF contents were higher (P<0.01); Meantime,the activities of eNOS?TNOS and SOD increased (P<0.01)while the content of MDA decreased(P<0.01).ConclusionRiboflavin pretreatment lessening ischemia/reperfusion injury in isolated perfused rat heart suggests that the protective mechanism might be associated with safeguarding the coronary endothelium and NO-mediated coronary vasodilation,hence increasing coronary effluent flow,enhancing anti-oxidation.