Pisarri T E, Jonzon A, Coleridge J C, Coleridge H M
Cardiovascular Research Institute, University of California, San Francisco 94143-0130.
J Appl Physiol (1985). 1990 May;68(5):1997-2005. doi: 10.1152/jappl.1990.68.5.1997.
We examined the ability of rapidly adapting receptors (RARs) to monitor changes in dynamic lung compliance (Cdyn) in anesthetized spontaneously breathing dogs by recording RAR impulses from the vagus nerves. We decreased Cdyn in steps through the physiological range by briefly restricting lung expansion with an inflatable cuff around the chest and recording the response after deflating the cuff; we restored Cdyn to control by hyperinflating the lungs. Of 45 RARs, 34 were stimulated by a 40 +/- 2% reduction in Cdyn, their inspiratory discharge increasing on average more than threefold. Two-thirds of responsive RARs were stimulated by less than or equal to 20% reductions in Cdyn; in most, firing increased proportionately with lung stiffness (1/Cdyn) as Cdyn was decreased further. Stimulation by reduced Cdyn was not simply a function of the concomitant increase in transpulmonary pressure, because similar increases in pressure produced by increasing tidal volume produced smaller increases in firing. RAR stimulation was unaffected by atropine and, hence, was not dependent on neurally mediated changes in bronchomotor tone. Our results indicate that during spontaneous breathing RARs provide a signal inversely proportional to Cdyn.
我们通过记录迷走神经的快速适应感受器（RARs）冲动，研究了麻醉状态下自主呼吸犬中RARs监测动态肺顺应性（Cdyn）变化的能力。我们通过用围绕胸部的充气袖带短暂限制肺扩张，在生理范围内逐步降低Cdyn，并在袖带放气后记录反应；我们通过肺过度充气将Cdyn恢复至对照水平。在45个RARs中，34个在Cdyn降低40±2%时受到刺激，其吸气放电平均增加超过三倍。三分之二的反应性RARs在Cdyn降低小于或等于20%时受到刺激；在大多数情况下，随着Cdyn进一步降低，放电与肺硬度（1/Cdyn）成比例增加。Cdyn降低引起的刺激并非仅仅是跨肺压同时增加的结果，因为潮气量增加产生的类似压力增加引起的放电增加较小。RAR刺激不受阿托品影响，因此不依赖于神经介导的支气管运动张力变化。我们的结果表明，在自主呼吸过程中，RARs提供与Cdyn成反比的信号。
