乙酰半胱氨酸对大鼠心肌缺血/再灌注后心梗面积和细胞凋亡的影响

Effects of N-acetylcysteine on ischemia/reperfusion-induced cardiocyte necrosis and apoptosis

目的观察乙酰半胱氨酸(NAC)对大鼠心肌缺血/再灌注(I/R)后心梗面积和细胞凋亡的影响。方法以穿线结扎左冠脉制备心肌I/R模型,36只大鼠随机分成假手术组(S组,n=12)、I/R组(n=12)和I/R+NAC治疗组(N组,n=12),检测各组心肌梗死范围、血浆肌酸激酶同工酶-MB(CK-MB)活性、心肌丙二醛(MDA)含量。分别以HE染色光镜下观察心肌组织病理学变化,原位末端标记法(TUNEL)检测心肌凋亡细胞及免疫组化法检测心肌半胱氨酸天冬氨酸蛋白酶-3(Caspase-3)的表达。结果心肌I/R后心肌梗死范围明显,血浆CK-MB活性和MDA含量增高,心肌细胞坏死增多。NAC干预后心肌梗死范围缩小,CK-MB活性和MDA含量下降,心肌细胞坏死程度较轻。N组心肌细胞凋亡指数、心肌组织中Caspase-3蛋白表达显著低于I/R组(P<0.01)。结论NAC可缩小大鼠I/R后心肌梗死范围,减少心肌细胞凋亡,对缺血再灌注心肌有保护作用。

Objective To study the effects of N-acetylcysteine （NAC） on ischemia/reperfusion （I/R）-induced myocardial injury and myocyte apoptosis in rats. Methods The I/R heart model was made by ligation of the left anterior descending coronary artery （LAD） close to its origin. The LAD was occluded for 30 rain followed by removal of ligation to allow subsequent reperfusion for 3 h. 36 rats were divided randomly into sham-operated （S） group, I/R group and NAC （N） group, infarct size （IS/AAR%） was measured in I/R group and N group. Malondialdehyde（MDA） and creatine kinase isoenzyme-MB（CK-MB） were measured,the apoptosis index （AI） by TUNEL staining, the number of the cells positive for Caspase-3 and positive expression index（PEI） were calculated. Results NAC decreased the infarct size compared with I/R group in IS/AAR%, CK-MB, and MDA （P〈0. 01）. AI and Caspase-3 PEI of I/R group were higher than those of N group （P〈0. 01）. Conclusion NAC can decrease the infarct size and attenuated cardiomyocyte apoptosis, which has protective effects on I/R myocardium.