超速驱动诱发大鼠离体心脏心肌顿抑的研究

Research on Overdriving-Induced Myocardial Stunning of Isolated Rat Heart

目的:通过电超速驱动模拟运动负荷诱发心肌顿抑现象,建立离体大鼠心脏运动性心肌顿抑模型。方法:将36只SPF级成年雄性SD大鼠随机分6组,用电刺激模拟运动负荷的方法来对大鼠离体心脏施加超速驱动,并根据驱动时间的不同进行分组,再分别测量记录各组驱动前后各指标的变化情况加以分析。结果:(1)各组左心室收缩压、发展压在驱动全过程呈下降趋势,舒张压呈上升趋势,而驱动前组间室内压无明显差异。(2)各组冠状动脉流出液CK、LDH在驱动前无明显差异,驱动后各实验组水平均高于对照组。(3)驱动20min组和30min组的心肌坏死率明显高于其他组,而其他组两两比较无组间差异。结论:(1)运动性心肌顿抑存在。(2)过长的高心率负荷将不再发生心肌顿抑现象而出现大面积心肌坏死。(3)本实验中,运动性心肌顿抑存在于5min组和10min组中。

Objective ： To establish exercise - induced myocardial stunning model of isolated rat heart by using electrical overdriving to simulate load - induced myocardial stunning. Methods ： 36 SPF male rats are selected and randomly divided into 6 groups. Overdriving is carried out on isolated rat heart by means of electric stimulation simulated load. Groups are divided according to the different driving time. Index change for each group before and after the driving is recorded. Results ： the PSP and DP of each group show a decreasing tendency in the whole process, while the EDP shows an increasing tendency. There is no marked difference in the ventricular pressure; there is no marked difference in the coronary CK and LDH for each group before the driving, while after the driving the experimental group is higher than the control group ; the heart muscle necrosis percentage of 20 - minute and 30 - minute driving groups are higher than that of other groups, while no marked difference is found among other groups. Conclusion： the exercise - induced myocardial stunning exists; prolonged high heart rate load wont generate myocardial stunning but it will generate wide myocardiolysis. In this experiment, exercise -induced myocardial stunning exists in the 5 -minute and 10 -minute groups.