Mohan M, Rai U C
Indian J Physiol Pharmacol. 1975 Apr-Jun;19(2):51-7.
It is generally believed that the stimulation of vagus nerve has no direct effect on ventricular myocardium. But recent work has demonstrated clear-cut negative inotropic effect of vagal stimulation on ventricles. In an attempt to study further the effect of vagal stimulation on heart, 15 dogs were studied hemodynamically under nembutal anaesthesia. Bilateral vagotomy caused 9% elevation of heart rate whereas arterial pressure and cardiac output increased by 5% and 3% respectively. Stroke volume output decreased by 8%. Stimulation of the cut peripheral end of vagus caused cardiac standstill followed by vagus escape. During the steady state of vagus escape there was marked reduction in arterial pressure, heart rate and cardiac output, but the stroke volume was significantly elevated above the mean control. These findings suggest that when heart rate decreases, the stroke volume increases in order to restore the decreased cardiac output and that this happens inspite of the negative inotropic effect of vagal stimulation. Thus the Frank-Starling mechanism has a very significant role in an intact organism with normal hemodynamics.
一般认为，迷走神经刺激对心室肌没有直接影响。但最近的研究表明，迷走神经刺激对心室有明确的负性肌力作用。为了进一步研究迷走神经刺激对心脏的影响，在戊巴比妥麻醉下对15只狗进行了血流动力学研究。双侧迷走神经切断术使心率升高9%，而动脉压和心输出量分别增加5%和3%。每搏输出量减少8%。刺激切断的迷走神经外周端会导致心脏停搏，随后出现迷走神经逸搏。在迷走神经逸搏的稳定状态下，动脉压、心率和心输出量显著降低，但每搏输出量明显高于平均对照水平。这些发现表明，当心率降低时，每搏输出量增加以恢复降低的心输出量，尽管存在迷走神经刺激的负性肌力作用。因此，弗兰克-斯塔林机制在具有正常血流动力学的完整机体中具有非常重要的作用。
