Gauda E B, Carroll T P, Schwartz A R, Smith P L, Fitzgerald R S
Department of Pediatrics, Johns Hopkins Medical Institutions, Baltimore, Maryland 21205.
J Appl Physiol (1985). 1994 Jun;76(6):2656-62. doi: 10.1152/jappl.1994.76.6.2656.
To investigate the influence of phasic pulmonary stretch receptors (n = 6) and chemoreceptors (n = 7) on the reflex response of the genioglossus (GG) muscle and diaphragm (DIA) to upper airway (UAW) negative pressure, we measured the response of the GG and DIA electromyogram (EMG) to three challenges: 1) negative pressure applied to the UAW during normoxia and hypercapnia, 2) end-expiratory tracheal occlusion, and 3) application of UAW negative pressure simultaneous with tracheal occlusion in spontaneously breathing tracheotomized anesthetized cats. Peak GG EMG was greatest when UAW negative pressure and end-expiratory tracheal occlusion were combined. No GG EMG activity was seen when UAW negative pressure was applied alone unless the animal was vagotomized or hypercapnic. DIA EMG increased in response to UAW negative pressure combined with occlusion. However, the increase in peak GG EMG was significantly greater than for the DIA with the same challenge. DIA EMG amplitude increased in response to occlusion alone but did not change when UAW negative pressure was applied alone. In the cat, phasic feedback from phasic pulmonary stretch receptors is a potent inhibitor of reflex activation of the GG in response to negative pressure applied to the UAW, which can be overridden by an increase in chemoreceptor drive.
为了研究相位性肺牵张感受器（n = 6）和化学感受器（n = 7）对上气道（UAW）负压作用下颏舌肌（GG）和膈肌（DIA）反射反应的影响，我们测量了GG和DIA肌电图（EMG）对三种刺激的反应：1）在常氧和高碳酸血症状态下对上气道施加负压；2）呼气末气管阻塞；3）在自主呼吸的气管切开麻醉猫中，同时施加UAW负压和气管阻塞。当UAW负压和呼气末气管阻塞同时存在时，GG EMG峰值最大。单独施加UAW负压时，除非动物进行了迷走神经切断或处于高碳酸血症状态，否则未见GG EMG活动。DIA EMG在UAW负压与阻塞联合作用时增加。然而，在相同刺激下，GG EMG峰值的增加显著大于DIA。DIA EMG幅度在单独阻塞时增加，但在单独施加UAW负压时不变。在猫中，相位性肺牵张感受器的相位性反馈是对UAW施加负压时GG反射激活的有效抑制因素，而化学感受器驱动的增加可克服这种抑制。
