Sanii R, Younes M
Department of Medicine, University of Manitoba, Winnipeg, Canada.
J Appl Physiol (1985). 1988 Feb;64(2):511-20. doi: 10.1152/jappl.1988.64.2.511.
Inspiratory duration (TI) increases during inspiratory resistive loading in conscious humans. To ascertain whether this response is related to the temporal pattern of pressure perturbation (reaching a peak in early or midinspiration and declining subsequently) we compared the response of nine normal subjects to a usual resistor (narrow tube, RES) with their response when mouth pressure was reduced in a sinusoidal fashion during inspiration (SIN). Whereas the negative pressure pattern was similar with both loads (peak negative pressure near midinspiration), there was no relation between pressure and flow in the case of sinusoidal loading. Each experiment consisted of two loading periods, 4 min each, and three unloaded periods, also 4 min each, bracketing the periods of loading. The order of RES and SIN was randomized. TI during loading was compared with the average TI of the preceding and following unloaded periods. TI increased 0.74 +/- 0.12 and 0.27 +/- 0.05 (SE) s during RES and SIN, respectively (P less than 0.01). We conclude that the temporal pattern of pressure change during resistance breathing plays a small role in mediating the TI prolongation. Coupling between flow and the pressure perturbation appears to be an important determinant of TI prolongation.
在清醒的人类中，吸气阻力负荷增加时吸气持续时间（TI）会延长。为了确定这种反应是否与压力扰动的时间模式（在吸气早期或中期达到峰值，随后下降）有关，我们比较了9名正常受试者对普通电阻器（细管，RES）的反应以及他们在吸气期间以正弦方式降低口腔压力时（SIN）的反应。尽管两种负荷下的负压模式相似（吸气中期附近的负压峰值），但在正弦负荷情况下，压力与流量之间没有关系。每个实验包括两个负荷期，各4分钟，以及三个无负荷期，同样各4分钟，夹在负荷期之间。RES和SIN的顺序是随机的。将负荷期间的TI与前后无负荷期的平均TI进行比较。RES和SIN期间，TI分别增加了0.74±0.12和0.27±0.05（SE）秒（P<0.01）。我们得出结论，阻力呼吸期间压力变化的时间模式在介导TI延长中起的作用较小。流量与压力扰动之间的耦合似乎是TI延长的一个重要决定因素。
