柚皮苷对大鼠心肌缺血/再灌注损伤细胞凋亡的影响及作用机制

Effect of Naringin on cell apoptosis in rats with myocardial ischemia/reperfusion injury

目的观察柚皮苷(Naringin,Nar)对大鼠心肌缺血/再灌注损伤(myocardial ischemia/reperfusion injury,MI/RI)细胞凋亡的影响,并探讨其作用机制。方法将10只大鼠经冠状动脉左前降支结扎30 min,再灌注120 min,建立MI/RI模型;低、中、高Nar干预组大鼠分别用10、20和40 mg/kg的Nar灌胃,1次/d,连续给药7 d,末次灌胃给药后60 min,进行MI/RI手术(同MI/RI模型组),每组10只;同时设假手术组(在冠状动脉前降支下只穿线不结扎)。采用TUNEL染色法检测细胞凋亡情况,Western blot法检测心肌组织中葡萄糖调节蛋白78(glucose-regulated protein78,GRP78)的表达水平。结果与假手术组比较,MI/RI模型组大鼠心肌细胞凋亡数和心肌组织中GRP78表达水平均明显升高(P<0.001);与MI/RI模型组相比,10、20和40 mg/kg Nar组大鼠心肌细胞凋亡数和心肌组织中GRP78表达水平均明显降低(P<0.01);与10 mg/kg Nar组比较,20和40 mg/kg Nar组的GRP78表达水平显著下调(P<0.001)。结论 Nar对MI/RI有明显保护作用,该作用可能与其抑制内质网应激(endoplasmic reticulum stress,ERS)相关蛋白GRP78的表达,减少细胞凋亡有关。

Objective To observe the effect of naringin（Nar） on cell apoptosis in rats with myocardial ischemia/reperfusion injury（MI/RI）and discuss the relevant mechanism. Methods The rat model of MI/RI was established by ligation of left anterior descending coronary artery of male Sprague Dawley rats for 30 min followed by reperfusion for120 min. The rats were divided into five groups,ten for each. The rats in low,moderate and high dose Nar groups were administered with Nar at dosages of 10,20 and 40 mg/kg by gavage once a day for 7 d respectively,and received MI/RI operation 60 min after the last gavage. Model rats untreated with Nar（MI/RI group） and the rats receiving sham operation（Sham operation group） were served as controls. Cell apoptosis was determined by TUNEL staining,while the expression level of glucose-regulated protein 78（GRP78） in myocardial tissue by Western blot. Results Compared with those in sham operation group,both the number of apoptotic cells and the expression level of GRP78 in the rats in MI/RI group increased significantly（P〈 0. 001）. However,compared with those in MI/RI group,both the number of apoptotic cells and the expression level of GRP78 of rats in low, moderate and high dose Nar groups decreased significantly（P〈 0. 01）. The expression levels of GRP78 in moderate and high dose Nar groups were significantly lower than that in low dose Nar group（P〈 0. 001）. Conclusion Nar significantly relieved the MI/RI,of which the mechanism might be related to inhibiting the expression of endoplasmic reticulum stress（ERS） and decreasing the cell apoptosis.