槲皮素对心肌缺血再灌注损伤的保护作用及机制研究

目的探讨槲皮素(QU)对心肌缺血再灌注(MI/R)损伤的保护作用及其作用机制。方法采用结扎左冠脉前降支30 min再灌注2 h的方法复制MI/R损伤大鼠模型,随机分为假手术组、模型组、QU组(25、50、100 mg/kg),每组10只,各组于术前1周开始灌胃给药,1次/d。再灌注后取心脏,染色法测定心肌梗死面积;免疫组化法测定心肌组织NF-κB和ICAM-1表达情况;取心肌匀浆,髓过氧化物酶(MPO)法测定中性粒细胞浸润情况。结果QU高、中剂量可分别缩小心肌梗死面积至25.00%、25.31%,与模型组(32.55%)比较差异有统计学意义(P<0.05);QU各剂量组心肌MPO活力分别降低至185.70、190.66、210.03 U/g,与模型组(311.72 U/g)比较差异均有统计学意义(P<0.05,P<0.01);QU各剂量组心肌组织ICAM-1阳性区面积百分比分别降至32.08%、32.65%、36.42%,与模型组(42.67%)比较差异有统计学意义(P<0.05,P<0.01);QU高、中剂量可使心肌NF-κB的表达水平分别降低至55.23%、54.90%,与模型组(61.05%)比较差异有统计学意义(P<0.05)。结论QU预处理可保护MI/R所致心肌损伤,其机制与抑制中性粒细胞浸润、下调NF-κB和ICAM-1的表达等有关。

Study of protective effect and the mechanisms of quercetin on myocardial ischemia/reperfusion injury

Objective To investigate the protective effect and the mechanisms of quercetin ( QU) on myocar-dial ischemia/reperfusion ( MI/R) injury. Methods Rat model of MI/R injury was established by coronary artery ligation for 30 min followed by 120 min reperfusion. The rats were divided randomly into 5 groups ( n =10 ): sham group,model group,QU groups (25,50,100 mg/kg). QU was orally administered once daily since 7 d before opera-tion. The area of myocardial infarction was recorded after reperfusion. The myocardial ICAM-1 and NF-κB activities were detected by immunohistochemistry. The MPO activity in heart homogenate was detected. Results The area of myocardial infarction in QU (50,100 mg/kg) groups was reduced respectively,there being significant difference be-tween QU (50,100 mg/kg) groups and model group (P<0. 05). The MPO activity in QU groups was lower than that of model group (P<0. 05,P<0. 01). The ICAM-1 positive rates of heart in QU groups decreased (P <0. 05,P <0. 01). The NF-κB positive rates in QU (50,100 mg/kg) groups decreased,and there were significant differences be-tween QU (50,100 mg/kg) groups and model group (P<0. 05). Conclusion QU pretreatment can protect against MI/R injury by the inhibition of neutrophil infiltration and down-regulation of ICAM-1 and NF-κB expression.