Shimizu T, Peterson D F, Bishop V S
Am J Physiol. 1979 Oct;237(4):H528-34. doi: 10.1152/ajpheart.1979.237.4.H528.
In anesthetized cats with aortic nerves sectioned and carotid arteries occluded, we determined the role of cardiac sympathetic nerves on the tonic inhibitory restraint by cardiac vagal afferents on the cardiovascular system. The effect of afferent vagal blockade on mean arterial pressure and cardiac contractility was determined when sympathetic tone to the heart was altered. Bilateral cardiac sympathectomy produced a significant decrease in left ventricular dP/dt and attenuated the arterial pressure response to afferent vagal cold block to less than 40% of the control. The increase in dP/dt normally observed with vagal blockade was also reduced significantly. Increasing dP/dt by efferent stimulation of cardiac sympathetic nerves restored the arterial pressure response to vagal blockade to near control levels. While the vagal inhibitory activity appeared to be dependent on the resting dP/dt, left ventricular peak pressure did not seem to be contributing to the reflex. Thus, the inhibitory effects of vagally mediated reflexes from the heart which contribute to arterial pressure regulation appear to be influenced by changes in cardiac contractility induced by cardiac sympathetic nerve stimulation.
在切断主动脉神经并结扎颈动脉的麻醉猫中，我们确定了心脏交感神经在心脏迷走传入神经对心血管系统的紧张性抑制性约束中的作用。当心脏的交感神经张力改变时，确定了迷走传入神经阻滞对平均动脉压和心脏收缩力的影响。双侧心脏交感神经切除术使左心室dp/dt显著降低，并使对迷走传入神经冷阻滞的动脉压反应减弱至对照的40%以下。通常在迷走神经阻滞后观察到的dp/dt增加也显著降低。通过传出刺激心脏交感神经增加dp/dt可使对迷走神经阻滞的动脉压反应恢复到接近对照水平。虽然迷走神经抑制活动似乎依赖于静息dp/dt，但左心室峰值压力似乎对该反射没有作用。因此，来自心脏的迷走神经介导反射的抑制作用有助于动脉压调节，似乎受到心脏交感神经刺激引起的心脏收缩力变化的影响。
