一次大负荷跑台运动后大鼠心脏力-电变化和组织病理学观察

The Changes in Force-electricity and Histopathology of Myocardium in Rats after Acute Heavy Load Exercise

目的:观察一次定量大负荷跑台运动后大鼠心脏心肌力-电变化和心肌组织病理学变化。方法:22只心电图正常SD大鼠随机分为对照组(n=8)和运动组(n=14)。采用BL-420E+型四道生理记录仪连续测定运动组一次定量大负荷跑台运动后0、5、10、20、30、50、70、90、110 min的心电图和左心室收缩功能,并于运动后110 min处死;对照组安静状态麻醉测定心电图和左心室收缩功能,麻醉后110 min处死。取材行心肌苏木精-伊红染色。根据运动后的心电变化,又将运动组分为心电异常组(ST段下压为异常,n=8)和心电无异常组(n=6)。结果:(1)大负荷运动后心电异常组大鼠左心室心肌收缩压和最大上升速率的时相变化不同步,运动后20和70 min心肌收缩力出现阶段性低值,而运动后15、90 min时+dp/dtmax出现阶段性低值,运动后110 min均恢复正常。(2)运动后心电异常组心电图出现T波倒置或低平、ST-T下移、J点下移等现象,T波和J点值均在运动后15、50min出现阶段性低值,T波运动后110 min恢复,接近正常,而J点值尚未完全恢复。(3)三组苏木精-伊红染色评分,两两组间比较均无显著性差异。结论:大负荷运动后大鼠心肌组织染色未见病理性改变,大鼠恢复期心脏力-电变化表现为短时可逆性心肌收缩功能障碍和心电异常变化。

Objective To observe the changes in force-electricity and histopathology of myocardium in rats after a quantitative heavy load exercise.Methods Twenty adult male SD rats were randomly divided into control group（n = 8） and exercise group（n = 14）.Exercise group was divided into abnormal ECG group（abnormal ST segment,n = 8） and normal ECG group（n = 6） according to ECG changes after exercise.Electrocardiogram and cardiac function in exercise group were recorded at 0,5,10,20,30,50,70,90,and 110 min after a quantitative heavy load exercise through a physiological data recorder,and rats in exercise group were killed 110 min after treadmill exercise;and rats in control group were killed 110min after anesthesia;Then the histology of cardiac front wall of rats in both groups was observed.Results（1）The phase changes in LVESP and ＋dp/dtmax were not synchronized after a quantitative heavy load exercise,the LVESP decreased 20 and 70 min after treadmill exercise,while the ＋dp/dtmax decreased 15 and 90 min after treadmill exercise,and both recovered to normal after treadmill exercise with 110 min.（2）The T wave and J points lowered 15 and 50 min after treadmill exercise,and T wave recovered to normal 110 min after treadmill exercise when J points had not been fully restore.（3）HE dyeing showed no significant difference between the two groups.Conclusion There was no pathological changes in rat myocardium after a quantitative heavy load exercise,the left ventricular force-electricity change after exercise was transient and reversible.