胺碘酮对兔心肌缺血/再灌注心肌细胞凋亡及Bcl-2、Bax蛋白表达的影响

目的:探讨胺碘酮(AM)对兔心肌缺血/再灌注损伤(I/RI)心肌细胞凋亡及凋亡相关蛋白Bcl-2、Bax表达的影响。方法:将60只新西兰大白兔随机分为假手术（Sham）组、缺血/再灌注（I/R）组和AM组，每组20只。Sham组开胸只穿线不结扎血管，而其余两组开胸并结扎兔左冠状动脉回旋支制备I/R无复流模型。应用硫磺素 S染色评估心肌无复流面积。经膜联蛋白V-异硫氰酸荧光素（annexin V-FITC）和碘化丙啶(PI)双标记后，应用流式细胞术检测心肌细胞并计算凋亡率。采用免疫组化染色法检测心肌细胞中Bcl-2、Bax蛋白的表达。结果:①在缺血范围差异无统计学意义的条件下，AM组无复流范围显著小于I/R组(t=4.483，P<0.01)。②与Sham组相比，I/R组和AM组细胞的凋亡率明显增加(F=315.25，P<0.01)。与I/R组相比，AM组细胞的凋亡率明显降低(F=315.25，P<0.01)。③与Sham组相比，I/R组和AM组Bcl-2、Bax蛋白的表达明显增加分别为(F=29.01，P<0.01和F=214.45，P<0.01)。与I/R组相比，AM组Bcl-2蛋白的表达明显增加(F=29.01，P<0.01)；Bax蛋白的表达明显减少(F=214.45，P<0.01)。与I/R组相比，AM组Bcl-2/Bax比值明显增加(F=97.61，P<0.01)。结论:AM可能通过具有抗I/R心肌细胞凋亡从而减轻无复流范围，至于抗凋亡和减轻无复流的具体机制有待进一步明确。

Effects of amiodarone on cardiomyocyte apoptosis and expressions of Bcl 2 and Bax protein after ischemia/reperfusion injury in rabbits

AIM:To investigate the effect of amiodarone on cardiomyocyte apoptosis and expressions of Bcl 2 and Bax protein after ischemia/reperfusion (I/R) injury in rabbits. METHODS: Sixty mature rabbits were randomized into sham group, I/R group and amiodarone (AM) group with 20 rabbits in each group. I/R group and AM group were subjected to 90 min of occlusion in the left circumflex artery followed by 2 h of reperfusion to establish the myocardial I/R injury model. After 120 min reperfusion, the no reflow (NR) areas were determined by thioflavin S. Apoptosis rate was determined with flow cytometer after AnnexinV fluorescein isothiocyanate (FITC) and propidium iodide (PI) staining. Protein expressions of Bcl 2 and Bax were studied by immunohistochemical staining and the ratios of Bcl 2/Bax were calculated. RESULTS: The NR area in the AM group decreased significantly compared with the I/R group (t=4483, P<005). The apoptosis rates of cardiomyocyte in both I/R and AM groups were significantly higher than in the sham group (F=80090, P<001). Compared with that in the I/R group, the apoptosis rate of cardiomyocytes significantly decreased in the AM group (F=80090, P<001) and compared with that in sham group, expressions of Bcl 2 and Bax protein increased in both I/R and AM groups (F=2901, P<001), (F=21445, P<001). Expression of Bcl 2 protein in the AM group was higher (F=2901, P<001) and the expression of Bax protein was significantly lower (F=21445, P<001) than in the I/R group. Compared with that in the I/R group, ratios of Bcl 2/Bax increased significantly (F=9761, P<001). CONCLUSION: Amiodarone may improve NR accompanied by inhibiting cardiomyocyte apoptosis induced by I/R injury in rabbits. The mechanism between anti apoptosis and reduction of the NR remains to be further clarified.