不同运动训练对大鼠心脏功能和副交感神经的影响研究

Effects of Different Intensity Exercise Training on Rats Cardiac Function and Parasynpathetic Nerve

目的:探讨有氧训练和大强度疲劳训练对大鼠心脏功能及左心室胆碱能神经和M2受体表达的影响。方法:3月龄雄性Sprague-Dawley大鼠36只,随机分为3组:安静对照组,有氧训练组和疲劳训练组。采用跑台训练方式,建立大鼠有氧训练和疲劳训练模型,采用多导生理记录仪(Powerlab/4SP,AD Instruments,Australia)测试大鼠血流动力学,组织化学Karnovsky-Roots法和免疫组化SABC法观察左心室胆碱能神经和M2受体的表达。结果:有氧训练组与安静对照组及疲劳训练组相比收缩压(SBP),舒张压(DBP)没有显著变化,但心率(HR)显著降低(P<0.05),左室内压峰值(LVSP)、左室内压最大上升速率(±dP/dtmax)显著升高(P<0.05);左心室胆碱能神经和M2受体表达显著上调(P<0.05);疲劳训练组与安静对照组及有氧训练组相比,HR和左室末期舒张压(LVEDP)增加,LVSP和±dP/dtmax降低;左心室胆碱能神经和M2受体表达显著下调(P<0.05)。结论:不同强度运动训练可使心脏功能、胆碱能神经和M2受体发生不同程度的改变,有氧训练可提高大鼠心脏功能,上调胆碱能神经和M2受体;大强度疲劳训练可使心脏功能紊乱,下调胆碱能神经和M2受体。推测不同运动强度造成心脏功能的改变可能与运动诱导心脏副交感神经调控能力改变有关。

The purpose of this study was to investigate the effects of aerobic and fatigue training on the cardiac function and expression of cholinesterase positive nerves and M2 receptors in rat＇ left ventricles. Method： 36 three-month-old male Sprague-Dawley rats were randomly divided into three groups： control group, aerobic training group and exercise induced-fatigue group. Through using the treadmill with increased load running training way, an aerobic and fatigue training model of rats was established. The hemodynamics was monitored by multichannel physiologic recorder （Powerlab/4SP, AD Instruments, Australia）. Karnovsky-Roots histochemieal staining and immunochemieal streptavidin-biotin complex staining were used to test the distribution of cholinesterase-positive nerves and M2 receptors. Result： Compared with control group and fatigue training group, systolic blood pressure （SBP） and diastolic blood pressure （DBP） changes no significantly in aerobic training group, but heart rate （HR） were decreased significantly （P〈0.05）, left ventricular systolic pressure （LVSP） and positive and negative maximal values of the instantaneous first derivative of left ventricular pressure （±dP/dt max） increased significantly （P〈0. 05）; Meanwhile,cholinesterase-positive nerves and M2 receptors up-regulation in left ventricles. Compared with control group and aerobic training group, HR and left ventricular end diastolic pressure （LVEDP） of fatigue training group increased, but LVSP and 4-dP/dt max decreased; furthermore, cholinesterase-positive nerves and M2 receptors of left ventricles down-regulation significantly（P〈0.05）. Conclusion： Different intensity exercise training affects the change of cardiac function, cholinesterase-positive nerves and M2 receptors. Aerobic training improved cardiac function, up-regulation cholinesterase-positive nerves and M2 receptors. However, fatigue training results in cardiac dysfunction, down-regulation cholinesterase-positive nerves and M2 receptors. So we presume that there has close relationship between the changes of cardiac function induced by training and the changes of parasynpathetic nerve system.