AMP579与腺苷对心肌缺血再灌注损伤的比较研究

AMP579 versus adenosine in myocardial ischemia reperfusion injury

目的比较AMP579和腺苷对大鼠心肌缺血再灌注损伤的保护作用及作用机制。方法 64只Wistar大鼠随机分为4组(每组各16只)。假手术组:开胸只穿线不结扎血管,麻醉维持150 min;缺血再灌注组(I/R):结扎冠状动脉左前降支(LAD)30 min,再灌注120 min;腺苷组:结扎LAD 30 min后,股静脉缓慢滴注腺苷305 ng·g-1·min-1,持续5 min,而后再灌注120 min;AMP579组:结扎LAD 30 min后,股静脉缓慢滴注AMP579305 ng·g-1·min-1,持续5 min,而后再灌注120 min。采用红四氮唑(TTC)法测量心肌梗死范围,TUNEL法观察各组心肌细胞凋亡数量,免疫组织化学SP法和Western blot观察Bcl-2和Bax蛋白的表达。结果与I/R组相比,腺苷组及AMP579组心肌梗死范围均明显缩小(P<0.01),心肌细胞凋亡率明显降低(P<0.01),Bax表达水平明显降低,Bcl-2表达水平明显升高(P<0.01),且AMP579组较腺苷组效果更为明显(P<0.05)。结论 AMP579和腺苷均可缩小心肌梗死范围,对缺血再灌注损伤的心肌起保护作用,且AMP579作用优于腺苷,其作用机制可能是通过上调Bcl-2蛋白的表达和下调Bax蛋白的表达,抑制再灌注心肌细胞的凋亡来实现的。

Objective To compare the protective effects and underlying mechanism of AMP579 and adenosine on myocardial ischemia reperfusion injury in rats. Methods Wistar rats（n =64） were divided into 4 groups（n =16each）. The sham operation group underwent thoracotomy with a stitch placed around but not ligating the artery and,maintenance anesthesia for 150 min; the ischemia and reperfusion group（I/R） had left anterior descending（LAD）coronary artery occluded for 30 min and reperfusion for 120 min; the adenosine group received slow irrigation of adenosine 305 ng·g^-1·min^-1for 5 min via femoral vein after the 30 min LAD artery occlusion, then reperfusion for 120min; the AMP579 group received slow irrigation of AMP579 305 ng·g^-1·min^-1was for 5 min via femoral vein after the30 min LAD occlusion, then reperfusion for 120 min. TTC method was used to measure area of myocardial infarction;TUNEL method was used to determine the number of apoptotic cardiomyocytes in each group; expressions of Bcl-2and Bax protein were measured by immunohistochemical SP method and Western blotting. Results Compared with the Group I/R, the myocardial infarction area, the rate of cardiomyocyte apoptosis, and the expression level of Bax protein were significantly reduced（P0.01） while the expression level of Bcl-2 was increased（P0.01） in both adenosine group and AMP579 group, and these effects in AMP579 group were more significantly than in the adenosine group（P0.05）. Conclusion Both AMP579 and adenosine may be cardio-protective against the ischemia reperfusion injury by reducing the myocardial infarct. Besides, AMP579 has a better effect than adenosine. The underlying mech-anism may be up-regulation of Bcl-2, down-regulation of Bax, and suppression of cardiomyocyte apoptosis induced by reperfusion.