力竭运动后不同时相大鼠心肌低氧诱导因子1α表达的变化

Change in the Expression of Rat Myocardial HIF-1α at Different Time Courses after Exhausted Exercise

目的:探讨力竭运动对心肌低氧诱导因子1α(HIF-1α)表达的影响。方法:90只健康成年雄性SD大鼠,分为安静对照组(n=10)和一次力竭游泳运动组(包括一次力竭后即刻组、6小时组、12小时组和24小时组,每组10只大鼠)、2周反复力竭游泳运动组(包括反复力竭后即刻组、6小时组、12小时组和24小时组,每组10只大鼠),建立一次力竭游泳和反复力竭游泳运动后心肌微损伤运动实验模型。两力竭运动组分别于最后一次力竭运动后即刻、6小时、12小时及24小时取材,安静对照组同期安静状态下取材。应用免疫荧光技术和图像分析方法测定各组大鼠心肌HIF-1α表达。结果:一次力竭游泳运动后即刻、6小时、12小时组大鼠左室、右室及室间隔HIF-1α蛋白表达均显著高于相同部位对照组蛋白表达(P<0.05);反复力竭运动后即刻组大鼠左心室HIF-1α蛋白表达显著高于对照组、6小时组及24小时组(P<0.05),即刻组、12小时及24小时组右心室HIF-1α蛋白表达均显著高于对照组(P<0.05)。结果提示,力竭运动后心肌低氧诱导因子-1α表达与心肌受损有关。

Objective To investigate the change in the expression of hypoxia-inducible factor-1α （HIF-1α） in rat myocardium at different time courses after exhausted exercise. Methods Ninety male Sprague-Dawley rats were divided into sedentary control group （n= 10）, single bout of exhausted exercise group （n= 40） and 2-week exhausted exercise group （n=40）. Rats were killed at Oh, 6hrs, 12hrs and 24hrs after exhausted exercise. The immunofluorescence technique and image-analysis method were used to study the change in the content of HIF-1α in rat myocardium. Results The content of HIF-1α in rat left and right ventricles and interventricular septum at Oh, 6hrs and 12hrs after single bout of exhausted exercise was significantly higher than that in control group （P〈0.05）. After 2-week exhausted exercise, the content of HIF-1α in rat left ventricular myocardium at Oh was significantly higher than that at 6hrs, 24hrs and that in control group （P〈0.05）, and the content of HIF-1α in rat right ventricular myocardium at Oh, 12hrs and 24hrs was significantly higher than that in control group （P〈0.05）. Conclusion The content of HIF-1α in rat myocardial tissue was increased obviously after exhausted exercise, which could be related to the exercise-induced myocardial ischemic damage.