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

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.

Creatine phosphate decreases the apoptosis and autophagy in myocardial ischemia/reperfusion rat heart

Objective To investigate the role of Creatine phosphate in myocardial ischemia-reperfusion (I/R) injury of rat heart in vivo. Methods 24 male SD rats weighing 200g～250g, were randomly divided into a Sham group; a I/R group and a Creatine phosphate（CP）group. CP group used 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 transmission electron microscopy. Expression of LC3-II was measured by the Western blotting. Results Comparing with Sham group, I/R aggravates injury of mitochondria, and increase autophagic vacuoles (AVs) (P<0.01) and apoptosis of cardiomyocytes (P<0.01). However, CP group alleviates injury of mitochondria and reduce 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 less increased than I/R-injured rats (P<0.05). Conclusion These results suggest that Creatine phosphate inhibits apoptosis and excessive autophagy to diminish the cell death induced by the myocardial I/R injury.