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.
出处
《中国运动医学杂志》
CAS
CSCD
北大核心
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
