Caldeira M P, Saldiva P H, Zin W A
Laboratório de Poluição Atmosférica Experimental, Faculdade de Medicina, Universidade de São Paulo, Brazil.
Respir Physiol. 1988 Jul;73(1):43-53. doi: 10.1016/0034-5687(88)90126-0.
In eight spontaneously breathing anesthetized rats airflow, volume, and tracheal pressure were measured. The passive and active mechanical properties of the respiratory system, the shape of the tracheal occlusion pressure wave (Potr), the decay of inspiratory muscle pressure during expiration, and parameters related to the control of breathing were computed both before and after bilateral cervical vagotomy. Pre- and post-vagotomy values of passive elastance, resistance, and time constant were similar. Active mechanics disclosed an increase of elastance and a decrease in resistance and in the time constant after vagotomy. The time course of Potr showed a downward concavity and was not modified by vagotomy in the range of control inspiratory times, whereas the shape of inspiratory muscle pressure decay during expiration was changed. The present data help to explain why after vagotomy the load-compensatory mechanisms are less effective.
在八只自主呼吸的麻醉大鼠中，测量了气流、容积和气管压力。计算了双侧颈迷走神经切断术前和术后呼吸系统的被动和主动力学特性、气管阻塞压力波（Potr）的形状、呼气期间吸气肌压力的衰减以及与呼吸控制相关的参数。迷走神经切断术前和术后的被动弹性、阻力和时间常数的值相似。主动力学显示迷走神经切断后弹性增加，阻力和时间常数减小。Potr的时间进程呈向下凹陷，在对照吸气时间范围内不受迷走神经切断术的影响，而呼气期间吸气肌压力衰减的形状发生了变化。目前的数据有助于解释为什么迷走神经切断术后负荷补偿机制的效果较差。
