一次性和反复性力竭运动后不同时相大鼠心肌Kir6.1的表达

目的:探讨力竭运动后不同时相大鼠心肌Kir6.1基因表达的变化特点.方法:健康雄性SD大鼠80只,分为一次力竭游泳运动组和2周反复力竭游泳运动组及相应安静对照组.依据Thomas实验方案,建立不同程度的运动性心肌微损伤实验动物模型.力竭运动后,分时相取材,采用RT-PCR定量反转录方法分析心肌离子通道亚基Kir6.1在mRNA表达水平的变化.结果:(1)一次性力竭运动和反复力竭运动后24小时,心房肌中Kir6.1基因表达均显著下降(P＜0.05).(2)一次性力竭运动和反复力竭运动后4、12、24小时,心室肌中Kir6.1基因表达均显著升高(P＜0.01).结论:(1)力竭运动后,心室肌Kir6.1基因的表达水平总体呈上调变化,心房肌Kir6.1基因的表达水平在运动后24小时呈下调变化.(2)心室肌Kir6.1基因表达的上调对运动心肌有保护作用,而心房肌Kir6.1基因表达下调是心房肌易损伤的机制之一.

The Gene Expression of Rat Myocardial Kir6.1 at Different Time Cases after Exhausted Exercise

Objective To investigate the gene expression of Kir6.1 in rat myocardial cell after exhausted exercises.Methods Eighty male Sprague-Dawley rats were randomly divided into sedentary control groups,single bout of exhausted exercise groups and daily exhausted exercise groups.Rats were killed at 4,12 and 24h after exhausted exercises,using RT-PCR to measure the mRNA level of Kir6.1 in myocardium.Results(1)After single bout of exhausted exercise and consecutive daily exhausted exercise,the gene expression of Kir6.1 in atrium was greatly decreased at 24h after exercise(P<0.01).(2)After single bout of exhausted exercise and consecutive daily exhausted exercise,the gene expression of Kir6.1 in ventricle was greatly improved at 4h,12h,24h after exercise(P<0.01).Conclusions(1) The gene expression of Kir6.1 in ventricle was greatly improved after exhausted exercise and the gene expression of Kir6.1 in atrium was significantly decreased at 24h after exercise.(2) The change of Kir6.1 gene expression in atrium might be one of the mechanisms which cause cardiac atrium damage.