Mink S N, Holtby S G, Berenzanski D J, Oppenheimer L, Anthonisen N R
Department of Medicine, University of Manitoba, Winnipeg, Canada.
J Appl Physiol (1985). 1989 Sep;67(3):1164-70. doi: 10.1152/jappl.1989.67.3.1164.
Five dogs underwent left pneumonectomy at 10 wk of age, whereas four littermates underwent a sham operation. At 26 wk of age the postpneumonectomy dogs had total lung vital capacity (VC) and lung weight similar to controls, but maximum expiratory flow was reduced. Pressure capsules were glued to right lower (RLL) and right cardiac (RCL) lobes, and alveolar pressures (PA) were measured during forced expiration. In postpneumonectomy dogs RLL and RCL both emptied more slowly than in control dogs, and emptying was especially delayed in RCL, which underwent the most growth. When both lobes deflated together, PA in RCL and RLL were similar in control dogs, but in postpneumonectomy dogs PA in RCL exceeded that in RLL by approximately 3 cmH2O from 80 to 20% VC. Because the higher driving pressure in RCL compensated for the relatively high resistance of RCL, the pattern of lobar emptying was relatively uniform over these lung volumes. This result was compatible with interdependence of lobar maximum expiratory flows. In addition, at PA of 6-10 cmH2O in postpneumonectomy dogs, maximum emptying rates of RCL were less when RCL deflated alone than when RCL and RLL emptied together, again demonstrating interdependence of lobar maximum expiratory flow.
五只狗在10周龄时接受了左肺切除术，而四只同窝出生的狗接受了假手术。在26周龄时，肺切除术后的狗的总肺肺活量（VC）和肺重量与对照组相似，但最大呼气流量降低。将压力胶囊粘贴在右下叶（RLL）和右心叶（RCL）上，并在用力呼气时测量肺泡压力（PA）。在肺切除术后的狗中，RLL和RCL的排空都比对照狗慢，并且RCL的排空尤其延迟，而RCL经历了最大的生长。当两个肺叶一起萎陷时，对照狗的RCL和RLL中的PA相似，但在肺切除术后的狗中，从80%到20%VC，RCL中的PA比RLL中的PA高出约3 cmH2O。由于RCL中较高的驱动压力补偿了RCL相对较高的阻力，并在这些肺容积上，肺叶排空模式相对均匀。这一结果与肺叶最大呼气流量的相互依赖性一致。此外，在肺切除术后的狗中，当PA为6-10 cmH2O时，RCL单独萎陷时的最大排空率低于RCL和RLL一起排空时的最大排空率，这再次证明了肺叶最大呼气流量的相互依赖性。
