心脏不停跳瓣膜置换手术对心肌线粒体凋亡通路的影响

Effect of on-pump beating-heart technique on mitochondrial-depedent myocardial apoptosis

目的探讨浅低温心脏不停跳手术对体外循环瓣膜置换患者心肌线粒体凋亡通路的影响。方法 50例择期行人工机械瓣膜置换手术的患者,使用随机数字表法分为心脏停搏组(停跳组)和浅低温心脏不停跳组(不停跳组),每组25例,其中停跳组在中度低温心脏停搏下完成心脏瓣膜置换手术,不停跳组在浅低温心脏跳动下完成手术。分别在打开和关闭右心房时取右心房组织标本,使用实时荧光定量PCR检测心肌组织Cyto C、Caspase-3 m RNA表达,使用Western Blot检测心肌组织Cyto C、Caspase-3蛋白相对含量,TUNEL法观察心肌细胞凋亡情况。结果打开右心房时心肌Cyto C、Caspase-3 m RNA与蛋白表达二组间比较,差异均无统计学意义(P>0.05);二组在关闭右心房时比打开右心房时m RNA及蛋白表达均升高,差异有统计学意义(P<0.05),但不停跳组升高幅度较小(P<0.05)。结论 浅低温心脏不停跳手术在一定程度上可以减轻术中心肌线粒体凋亡通路的激活,减轻心肌损伤。

Objective To investigate the effect of on-pump beating-heart technique on mitochondrial-depedent myocardial apoptosis in patients with heart valve replacements undergoing cardiopulmonary bypass（CPB）. Methods Fifty patients undergoing elective artificial mechanical heart valve replacements with CPB were randomly divided into conventional group and beating heart group, 25 cases in each group. While the conventional approach was used for 25 patients in conventional group, the heart was kept empty and beating throughout the operation in beating heart group. Right atrial myocardial tissue samples were taken to detect myocardial Cyto C and Caspase-3 m RNA expressions using real-time fluorescence quantitative PCR and protein expressions using Western blot when the right atrium was opened and closed. Results In both groups, compared with the baseline values, m RNA and protein levels of Cyto C and Caspase-3 were increased when the right atrium was closed. Compared to conventional group, the increasing degrees of Cyto C and Caspase-3 were significantly lower in beating heart group（P〈0.05）. Conclusion Beating-heart technique may reduce mitochondrial-dependent apoptosis of myocardial cells, and mitigate the damage of myocardium.