Smith L J, Inners C R, Terry P B, Menkes H A, Traystman R J
J Appl Physiol Respir Environ Exerc Physiol. 1979 May;46(5):966-72. doi: 10.1152/jappl.1979.46.5.966.
We studied the effects of hypocapnia and methacholine on small airways resistance (Rsaw) and collateral ventilation in anesthetized paralyzed dogs. The animals were ventilated with air while either 10% CO2 or air (hypocapnia) was infused through a segment obstructed with a fiber-optic bronchoscope. Measurements were made before and after instillation of methacholine into the obstructed segment. Collateral resistance (Rcoll) and Rsaw increased with hypocapnia and methacholine. The time constant for collateral ventilation increased with hypocapnia, but did not change with methacholine because of decreases in the compliance of the obstructed segment. We conclude that collateral channels respond to methacholine and hypocapnia in a manner similar to small airways and that local parasympathomimetic stimulation, unlike lung deflation does not increase the time constant for collateral ventilation.
我们研究了低碳酸血症和乙酰甲胆碱对麻醉性瘫痪犬小气道阻力（Rsaw）和侧支通气的影响。动物通过空气进行通气，同时通过被纤维支气管镜阻塞的节段注入10%二氧化碳或空气（低碳酸血症）。在向阻塞节段滴注乙酰甲胆碱之前和之后进行测量。侧支阻力（Rcoll）和Rsaw随着低碳酸血症和乙酰甲胆碱而增加。侧支通气的时间常数随着低碳酸血症而增加，但由于阻塞节段顺应性降低，乙酰甲胆碱对其没有影响。我们得出结论，侧支通道对乙酰甲胆碱和低碳酸血症的反应方式与小气道相似，并且局部拟交感神经刺激与肺萎陷不同，不会增加侧支通气的时间常数。
