力竭运动对大鼠心脏传导系统电压门控钠离子通道α亚基的影响  

The Expression of SCN5A in Cardiac Conduction System after Exhaustive Exercise

作　　者：常芸[1] 杨红霞[1] 薄冰[1] 

机构地区：[1]国家体育总局体育科学研究所,北京100061

出　　处：《中国运动医学杂志》2013年第11期980-986,共7页Chinese Journal of Sports Medicine

基　　金：国家体育总局科研所基本科研业务课题(12-25)资助

摘　　要：目的:探讨力竭运动后不同时相大鼠心脏窦房结、房室结和浦肯野氏纤维电压门控钠离子通道α亚基(SCN5A)基因和蛋白水平的表达特点,为阐明运动性心律失常发生机制提供实验依据。方法:100只健康成年雄性SD大鼠随机分为一次力竭运动组、反复力竭组及其相应的对照组,每组10只。分别于力竭运动后0、4、12及24小时取材,进行心电图、免疫荧光组化及实时荧光定量PCR分析,测试心脏窦房结、房室结和浦肯野氏纤维细胞离子通道因子SCN5A mRNA和蛋白表达。结果:不同力竭运动后,窦房结SCN5A mRNA表达运动后各时相组均显著低于其对照组(P<0.01),一次力竭运动后即刻、4小时窦房结SCN5A mRNA表达显著低于房室结(P<0.01)和浦肯野氏纤维(P<0.05)。反复力竭运动后即刻窦房结SCN5A mRNA表达显著低于房室结和浦肯野氏纤维(P<0.01)。结论:力竭运动可导致心脏传导系统细胞膜离子通道亚型SCN5A在mRNA和蛋白水平异常低表达,其中窦房结改变最明显和持久,其结果可能引起心脏起搏和传导功能异常,构成运动性心律失常的病理与发生机制。Objective To investigate the gene and protein expression characteristics of SCN5A in cardiac conduction system at different time-phrase after exhaustive exercise, in order to provide experimental evi- dence for clarifying the mechanism of exercise-induced arrhythmia. Methods 100 healthy adult male SD rats were randomly divided into 10 groups （ 10 rats per group） according to their time of sacrifice. They were sacri- ficed immediately and at 0 hour, 4 hours, 12 hours, and 24 hours after exhaustive swimming. The electrocar- diograms in all rats were obtained before sacrifice. The mRNA and protein expressions of SCN5A in the sino- atrial node, atrioventricular node, and Purkinje＇ s fiber cells were respectively analyzed by real-time fluores- cent quantitative PCR, immunochemistry and image analysis. Results As compared with the control group, the expressions of mRNA and protein of SCN5A in sinoatrial node significantly decreased at 4 hours, 12 hours, and 24 hours after exhaustive exercise （ P 〈 0.01 ）. The expressions of mRNA and protein of SCN5A in sinoatrial node were significantly lower than that in atrioventricular node and Purkinje＇s fiber immediately and 4 hours after single bout of exhaustive exercise （ P 〈 0.05 ）. The expressions of mRNA and protein of SCN5A in sinoatrial node were significantly lower than that in atrioventricular node and Purkinje＇ s fiber im- mediately after single bout of exhaustive exercise （ P 〈 0.01 ）. Conclusion Exhaustive exercise causes down- ward expressions of mRNA and protein of SCN5A in cardiac conduction system, especially in sinoatrial node, which probably results in abnormal cardiac sinus pacing and abnormal atrioventricular electrical conduction.

关 键 词：心脏传导系统 力竭运动 电压门控钠离子通道α亚基 

分 类 号：R87[医药卫生—运动医学]