Bates J H, Peslin R
Meakins-Christie Laboratories, McGill University, Montreal, Quebec, Canada.
J Appl Physiol (1985). 1993 Jul;75(1):405-11. doi: 10.1152/jappl.1993.75.1.405.
We measured tracheal pressure (Ptr), tracheal flow, and two alveolar pressures in five open-chest anesthetized and paralyzed dogs. The lungs were maintained at a fixed volume for 50 s while small amplitude oscillations in flow at 6 Hz were applied at the tracheal opening. The measurements of alveolar pressure showed that the resulting oscillations in Ptr were virtually entirely determined by airway resistance (Raw) and consequently gave accurate estimates of the same. A 20-mg bolus of histamine was given intravenously at the start of this period when Ptr was 0.5 kPa. After approximately 10 s the mean Ptr increased sharply by approximately 40% and plateaued after approximately 25 s. Raw, in contrast, continued to increase throughout the oscillation period. Furthermore, the increases in mean Ptr were virtually identical in all dogs, whereas the increases in Raw were highly variable among the dogs. Our results suggest that the increases in mean Ptr caused by histamine were due to contraction of distal elements in the lung, whereas the changes in Raw were due mainly to constriction of more central airways.
我们在五只开胸麻醉并瘫痪的犬身上测量了气管压力（Ptr）、气管流量以及两个肺泡压力。在气管开口处施加6赫兹的小幅度流量振荡时，肺被维持在固定容积50秒。肺泡压力测量结果显示，Ptr产生的振荡几乎完全由气道阻力（Raw）决定，因此能对气道阻力进行准确估计。在此期间开始时，当Ptr为0.5千帕时，静脉注射20毫克组胺推注量。大约10秒后，平均Ptr急剧增加约40%，并在大约25秒后达到平稳状态。相比之下，Raw在整个振荡期持续增加。此外，所有犬的平均Ptr增加几乎相同，而Raw的增加在犬之间差异很大。我们的结果表明，组胺引起的平均Ptr增加是由于肺远端成分的收缩，而Raw的变化主要是由于更中央气道的收缩。
