缺血/再灌注损伤后心肌神经生长因子的变化

目的：观察缺血／再灌注损伤后神经生长因子表达的变化，初步探讨神经生长因子在心肌缺血／再灌注损伤发生机理中的作用及对交感神经功能改变的影响。方法：选用SD大鼠随机分2组，每组各8只，分别为假手术组、缺血／再灌注损伤组（本组以非缺血／再灌注损伤区为自身对照）。通过阻断左冠状动脉左前降支建立在体大鼠工作心缺血／再灌注损伤模型，用免疫组化法检测神经生长因子在缺血／再灌注损伤组左心室缺血／再灌注损伤区、非缺血／再灌注损伤区及假手术组左心室心肌中表达的差别。结果：免疫组织化学法显示神经生长因子在假手术组的大鼠心肌、非缺血／再灌注损伤区心肌与缺血／再灌注损伤区心肌表达阳性率分别为34．34％、38．28％、51．05％，前两者之间差异无显著性（P〉0．05），但缺血／再灌注损伤区神经生长因子的表达量明显增高，与前两组比较差异有显著性（P〈0．01）。结论：神经生长因子在心肌缺血／再灌注损伤过程中明显增高，神经生长因子参与心肌缺血／再灌注损伤的发生发展及交感神经功能的改变。

Regulation of Nerve Growth Factor in Rat's hearts after ischemia and reperfusion

Objective:This study was to investigate the regulation of NGF after myocardial ischemia followed by reperfusion.Methods:16 Sprague-Dawley rats were randomly devided into two groups:a sham operation group used asa a control group and an ischemia-reperfusion group whose left ventricle was composed of ischemia-reperfusion area and no ischemia-reperfusion area used asa a self-control.The Model of ischemia /reperfusion was induced by 30-minute ligation of the left anterior descending coronary artery (LAD) and 3-hour reperfusion. Immunohistochemistry technique was used to detect the immunoreaction(IR) intensity of NGF in the ischemia-reperfusion area,no ischemia-reperfusion area,and sham-operated hearts.Results:The percentage of myocardium displaying IR for NGF in sham-operated hearts was34.34%,in no ischemia-reperfusion area was 38.28%.in ischemia-reperfusion area was 51.05%.The difference was not statistically significant(P>0.05)between sham-operated hearts and no ischemia-reperfusion area,but NGF was higher in the left ventricles subjected to ischemia and reperfusion than in those not subjected to ischemia and reperfusion and in sham-operated hearts(P<0.01).Conclusion:NGF in rat hearts is increased after myocardial ischemia and reperfusion. It suggests a role for NGF in the pathogenesis of reperfusion injury and in the alterations of cardiac sympathetic neuronal function after myocardial ischemia and reperfusion.