力竭运动后不同时相大鼠心肌连接蛋白43的变化

目的:探讨力竭运动后不同时相心肌连接蛋白43(Cx43)分布模式及含量的改变。方法:90只健康成年雄性SD大鼠,分为一次力竭运动组和2周反复力竭运动组及安静对照组,运动组采用游泳运动方式分别于力竭运动后即刻、6小时、12小时及24小时取材,应用免疫荧光技术和图像分析方法对大鼠心肌Cx43分布及含量的改变进行研究。结果:一次力竭运动和反复力竭运动后各时相组心肌Cx43分布模式发生明显改变,由端对端连接为主转变为侧对侧连接为主。一次力竭和反复力竭运动后各时相组左、右心室Cx43含量都显著低于安静对照组(P<0.05)。力竭运动后各时相组左、右心室Cx43含量在两种运动形式之间无显著性差异(P>0.05)。结论:一次力竭运动和反复力竭运动均可造成心肌Cx43的降解以及分布模式的改变,这可能是运动性心律失常的结构基础。

The Changes in Myocardial Connexin43 after Exhausted Exercise in Rats

Objective In order to investigate the changes in distribution and content of connexin 43 in myocardial tissue after exhausted exercise at different time points.Methods Ninety male Sprague-Dawley rats were divided into sedentary control group, single bout of exhausted exercise groups and 2-week exhausted exercise groups. Rats were killed at 0h, 6h, 12h and 24h after exhausted exercise. Immunofluorescence technique and image-analysis method were used to study the changes in distribution and content of Cx43 in myocardial tissue.Results After single bout of exhausted exercise and 2-week exhausted exercises, myocardial Cx43 distribution pattern at each time point revealed a remarkable change: from end-to-end distribution to side-to-side distribution predominantly. After single bout of exhausted exercise and 2-week exhausted exercises, left ventricular and right ventricular myocardial Cx43 content at each time point was remarkable lower than control group (P<0.05). After exhausted exercise, left ventricular and right ventricular myocardial Cx43 content at each time showed no remarkable difference between two different exercise forms (P>0.05).Conclusion Single bout of exhausted exercise and 2-week exhausted exercise could result in degradation and change in distribution pattern of myocardial Cx43, probably contributing to exercise-induced arrhythmia structurally.