The effect of chronic voluntary exercise on cardiovascular response to nonexercise stressor.

我们研究了10-12周的自愿轮跑训练对大鼠在笼子转换或制动应激下心血管和交感肾上腺反应的影响（实验1和2）。我们还研究了内源性CRF对自主跑步训练的中枢神经系统（CNS）作用的调节可能是训练后心血管对非运动应激反应改变的潜在因素之一（实验2）。在实验1中，与对照组（C）大鼠相比，训练组（T）大鼠在换笼或制动应激期间的平均动脉压和心率升高显著减弱。实验1中，制动应激时T组大鼠血浆NE水平有低于C组的趋势。这些结果表明，自愿跑步训练减弱心血管反应的非运动应激。然而，在实验2中，自愿跑步训练对转笼或制动应激的心血管反应没有影响。实验2在训练后期的每日自主跑距离比实验1短。因此，跑步距离可能是自主跑步训练对非运动性应激源心血管反应减弱的潜在因素。实验2未能评价自发跑步训练对内源性CRF中枢神经系统活动的调节是否是训练后心血管对非运动应激反应减弱的可能机制之一。

We investigated the effect of voluntary wheel running training for 10-12 wks on cardiovascular and sympathoadrenal responses to cage-switch or immobilization stress in rats (experiment 1 and 2). We also examined the possibility that the modulated central nervous system (CNS) actions of endogenous CRF with voluntary running training may be one of potential factors of the modified cardiovascular response to nonexercise stressor after training (experiment 2). In experiment 1, trained (T) rats exhibited significantly attenuated elevations in mean arterial pressure and heart rate compared with control (C) rats during cage-switch or immobilization stress. Plasma NE level tended to be lower in T rats than in C rats during immobilization stress in experiment 1. These results suggest that voluntary running training attenuates cardiovascular response to nonexercise stressor. In experiment 2, however, voluntary runing training had no effect on the cardiovascular response to cage-switch or immobilization stress. The voluntary running distance per day during the later periods of training was shorter in experiment 2 than in experiment 1. Therefore, the running distance may be potential factor of the attenuated cardiovascular response to nonexercise stressor with voluntary running training. Whether the modulated CNS actions of endogenous CRF with voluntary running training may be one of possible mechanisms of the attenuated cardiovascular response to nonexercise stressor after training, could not be evaluated in experiment 2.