磷酸肌酸减少大鼠缺血再灌注心肌细胞凋亡及自噬泡的数量

摘要

Objective To investigate the role of Creatine phosphate in myocardial ischemia-reperfusion (I/R) injury of rat heart.Methods Twenty-four male SD rats weighing 200 ～250 g,were randomly divided into a Sham group; a I/R group and a phosphocreative (CP)group.CP group were taken the intravenous administration of 4 mg/kg creatine phosphate sodium before the reperfusion.TUNEL method was used to detect apoptosis of cardiomyocytes.The formation of autophagosomes was observed by electron microscopy.Expression of LC3-Ⅱ was measured by the Western blot.Results Comparing with sham group,I/R aggravated injury of mitochondria,and increased autophagic vacuoles (AVs) (P ＜ 0.01) and apoptosis of cardiomyocytes (P ＜ 0.01).However,CP group alleviated injury of mitochondria and reduced autophagic vacuoles(P ＜ 0.05) and apoptosis of cardiomyocytes(P ＜0.05) comparing to I/R group.LC3-Ⅱ formation,an autophagy marker,was down-regulated in the CP group (P ＜ 0.01),which was less increased than I/R-injured rats (P ＜ 0.05).Conclusions Creatine phosphate inhibits apoptosis and excessive autophagy to diminish the cell death induced by the myocardial I/R injury.%目的 研究磷酸肌酸减少大鼠缺血再灌注心肌细胞凋亡及白噬的能力.方法 雄性SD大鼠24只,体质量200 ～ 250 g,随机均分为假手术(sham)组、缺血/再灌注(ischemia-reperfusion,I/R)组和磷酸肌酸钠(phosphocreatine,CP)干预组.其中CP组按4 mg/kg磷酸肌酸钠剂量于再灌注前经右股静脉注射.用TUNEL法检测心肌细胞凋亡；电子显微镜观察心肌细胞自噬泡的发生和线粒体的形态学改变；Western blot检测微管相关蛋白1轻链3-Ⅱ(LC3-Ⅱ)蛋白的表达.结果 I/R组与sham组相比,线粒体超微结构损伤加重,自噬泡数量增多(P＜0.01),心肌细胞凋亡率明显增加(P＜0.01)；CP干预组可减轻I/R组线粒体超微结构损伤,自噬泡数量减少(P＜0.05),降低心肌细胞凋亡率(P ＜0.05)；LC3-Ⅱ作为评价自噬强度的指标,I/R组与sham组相比,LC3-Ⅱ蛋白的表达明显上调(P＜0.01)；而CP与I/R组相比,该蛋白表达明显下调(P＜0.05).结论 磷酸肌酸通过减少大鼠缺血再灌注心肌细胞凋亡及自噬泡的数量,从而减轻心肌缺血再灌注损伤.