Mathew O P, Abu-Osba Y K, Thach B T
Respir Physiol. 1982 Aug;49(2):223-33. doi: 10.1016/0034-5687(82)90075-5.
Influences of pressure changes within the upper airway on respiratory frequency were studied in anesthetized rabbits. These reflex effects were investigated in two ways: (1) by applying sustained negative or positive pressures to isolated upper airway in vagally intact animals during tracheostomy breathing, and (2) by briefly occluding the nasal airways of vagotomized animals at end expiration. Negative pressure applied to isolated upper airway decreased the respiratory frequency (P less than 0.01). Decrease in respiratory frequency correlated with magnitude of pressure change. In contrast, positive pressures produced an increase in respiratory frequency (P less than 0.05). But, the increase in frequency correlated poorly with magnitude of positive pressure change. A post-stimulus effect lasting several breaths was seen following the release of both negative and positive pressures (P less than 0.01). Nasal occlusion in vagotomized animals was associated with an increase in Ti and Ttot of the first nasally occluded breath (P less than 0.05). Increase in Ti was not associated with an increase in peak diaphragmatic activity. This would result in decreased inspiratory load on the upper airway patency maintaining muscles by reducing the mean inspiratory pressure. Hence, these reflex responses to airway pressure could play a functional role in the maintenance of upper airway patency.
研究了麻醉兔上气道内压力变化对呼吸频率的影响。通过两种方式研究这些反射效应：（1）在气管切开呼吸期间，对迷走神经完整的动物的离体上气道施加持续的负压或正压；（2）在呼气末短暂阻塞迷走神经切断动物的鼻气道。对离体上气道施加负压会降低呼吸频率（P<0.01）。呼吸频率的降低与压力变化幅度相关。相比之下，正压会使呼吸频率增加（P<0.05）。但是，频率的增加与正压变化幅度的相关性较差。在释放负压和正压后均出现持续数次呼吸的刺激后效应（P<0.01）。迷走神经切断动物的鼻阻塞与第一次鼻阻塞呼吸的吸气时间（Ti）和总吸气时间（Ttot）增加有关（P<0.05）。Ti的增加与膈肌峰值活动的增加无关。这将通过降低平均吸气压力来减少对上气道通畅维持肌肉的吸气负荷。因此，这些对气道压力的反射反应可能在上气道通畅的维持中发挥功能性作用。
