Lian Zhe-Xun, Wang Fang, Fu Jun-Hua, Chen Zuo-Yuan, Xin Hui, Yao Ru-Yong
Department of Cardiology, The Affiliated Hospital of Qingdao University, Qingdao, Shandong 266003, P.R. China.
Department of Cardiology, The Third People's Hospital of Qingdao, Qingdao, Shandong 266000, P.R. China.
Exp Ther Med. 2016 Oct;12(4):2063-2068. doi: 10.3892/etm.2016.3563. Epub 2016 Aug 2.
The aim of the present study was to examine the post-infarct acute effect of adenosine-5'-triphosphate (ATP) on myocardial infarction (MI) size as well as its precise molecular mechanism. Sixty New Zealand white male rabbits were exposed to 40 min of ischemia followed by 180 min of reperfusion. The rabbits were intravenously administered 3 mg/kg of ATP (ATP group) or saline (control group) immediately after reperfusion and maintained throughout the first 30 min. The wortmannin+ATP, PD-98059+ATP, and 5-hydroxydecanoic acid (5-HD) sodium salt+ATP groups were separately injected with wortmannin (0.6 mg/kg), PD-98059 (0.3 mg/kg), and 5-HD (5 mg/kg) 5 min prior to ATP administration. MI size was calculated as the percentage of the risk area in the left ventricle. Myocardial apoptosis was determined using a TUNEL assay. Western blot analysis was performed to examine the levels of protein kinase B (Akt)/p-Akt and extracellular signal-regulated kinase (ERK)/p-ERK in the ischemic myocardium, 180 min after reperfusion. The infarct size was significantly smaller in the ATP group than in the control group (p<0.05). The infarct size-reducing effect of ATP was completely blocked by wortmannin, PD-98059 and 5-HD. Compared with the control group, cardiomyocyte apoptosis was significantly reduced in the ATP group, while this did not occur in the wortmannin+ATP, PD-98059+ATP and 5-HD+ATP groups. Western blot analysis revealed a higher myocardial expression of p-Akt and p-ERK 180 min following reperfusion in the ATP versus the control group. In conclusion, cardioprotection by postischemic ATP administration is mediated through activation of the reperfusion injury salvage kinase (RISK) pathway and opening of the mitochondrial ATP-dependent potassium channels.
本研究的目的是探讨5'-三磷酸腺苷（ATP）对心肌梗死后急性心肌梗死（MI）面积的影响及其精确的分子机制。60只新西兰雄性白兔经历40分钟缺血，随后再灌注180分钟。再灌注后立即给兔子静脉注射3mg/kg的ATP（ATP组）或生理盐水（对照组），并在最初30分钟内持续给药。渥曼青霉素+ATP组、PD-98059+ATP组和5-羟基癸酸钠（5-HD）+ATP组在给予ATP前5分钟分别注射渥曼青霉素（0.6mg/kg）、PD-98059（0.3mg/kg）和5-HD（5mg/kg）。MI面积以左心室危险区的百分比计算。使用TUNEL法测定心肌细胞凋亡。在再灌注180分钟后，进行蛋白质印迹分析以检测缺血心肌中蛋白激酶B（Akt）/磷酸化Akt（p-Akt）和细胞外信号调节激酶（ERK）/磷酸化ERK（p-ERK）的水平。ATP组的梗死面积明显小于对照组（p<0.05）。渥曼青霉素、PD-98059和5-HD完全阻断了ATP的梗死面积缩小作用。与对照组相比，ATP组心肌细胞凋亡明显减少，而渥曼青霉素+ATP组、PD-98059+ATP组和5-HD+ATP组未出现这种情况。蛋白质印迹分析显示，再灌注180分钟后，ATP组心肌中p-Akt和p-ERK的表达高于对照组。总之，缺血后给予ATP的心脏保护作用是通过激活再灌注损伤挽救激酶（RISK）途径和开放线粒体ATP依赖性钾通道介导的。
