Forster H V, Lowry T F, Pan L G, Erickson B K, Korducki M J, Forster M A
Department of Physiology, Medical College of Wisconsin, Milwaukee 53226.
J Appl Physiol (1985). 1994 Mar;76(3):1330-9. doi: 10.1152/jappl.1994.76.3.1330.
We determined the effect of pulmonary vagal (hilar nerve) denervation (HND) and diaphragm deafferentation (DD) on inspiratory load compensation. We studied awake intact (I; n = 10), DD (n = 5), HND (n = 4), and DD+HND (n = 7) ponies at rest and during mild (1.8 mph, 5% grade) and moderate (1.8 mph, 15% grade) treadmill exercise before, during, and after resistance of the inspiratory circuit was increased from approximately 1.5 to approximately 20 cmH2O.l-1.s. During the first loaded breath in I ponies at rest, inspiratory time (TI) increased, expiratory time decreased, and inspiratory drive increased. There were minimal changes after the first breath, and inspiratory minute ventilation (VI) and arterial PCO2 did not change (P > 0.10) from control values. On the first loaded breath during exercise, TI increased but inspiratory drive either did not change or decreased from control values. TI and drive increased after the first breath, but the increases were insufficient to maintain VI and arterial PCO2 at control levels. First-breath load compensation remained after DD, HND, and DD+HND, but after DD+HND tidal volume and VI were compensated 5-10% less (P < 0.05) than in I ponies. In all groups inspiratory drive, tidal volume, and VI were markedly augmented on the first breath after loading was terminated with a gradual return toward control. We conclude that diaphragm and pulmonary afferents contribute to but are not essential for inspiratory load compensation in awake ponies.
我们确定了肺迷走神经（肺门神经）去神经支配（HND）和膈肌传入神经切断术（DD）对吸气负荷代偿的影响。我们研究了清醒的完整状态（I组；n = 10）、DD组（n = 5）、HND组（n = 4）以及DD + HND组（n = 7）的小马，在静息状态下以及在轻度（1.8英里/小时，坡度5%）和中度（1.8英里/小时，坡度15%）跑步机运动期间及之后，当吸气回路阻力从约1.5 cmH₂O·l⁻¹·s增加至约20 cmH₂O·l⁻¹·s时的情况。在静息状态下的I组小马的第一次负荷呼吸期间，吸气时间（TI）增加，呼气时间减少，吸气驱动力增加。第一次呼吸后变化极小，吸气分钟通气量（VI）和动脉血PCO₂与对照值相比无变化（P > 0.10）。在运动期间的第一次负荷呼吸时，TI增加，但吸气驱动力与对照值相比要么没有变化要么降低。第一次呼吸后TI和驱动力增加，但增加幅度不足以将VI和动脉血PCO₂维持在对照水平。DD、HND以及DD + HND组在第一次呼吸时仍保留负荷代偿能力，但与I组小马相比，DD + HND组的潮气量和VI的代偿程度要低5 - 10%（P < 0.05）。在所有组中，当负荷终止后的第一次呼吸时，吸气驱动力、潮气量和VI均显著增加，并逐渐恢复至对照水平。我们得出结论，膈肌和肺传入神经对清醒小马的吸气负荷代偿有作用，但并非必不可少。
