Parker R E, Granger D N, Taylor A E
Am J Physiol. 1981 Nov;241(5):H732-9. doi: 10.1152/ajpheart.1981.241.5.H732.
Isogravimetric capillary pressures (Pci) and pre-(Ra) and postcapillary (Rv) pulmonary vascular resistances were estimated in isolated dog lungs when ventilated with 95% O2-5% CO2 and during alveolar hypoxia, which was simulated by ventilation with a 95% N2-5% CO2 gas mixture. In addition, the filtration coefficient (KF,C) was measured during alveolar hypoxia and compared with prehypoxic measurements. When both arterial and venous pressures were maintained constant during the alveolar hypoxia, Pci decreased from 8 to 6.9 mmHg, and total pulmonary vascular resistance increased from 0.040 to 0.083 (cmH2O . ml-1 . min . 100 g lung). Ra increased significantly from 0.027 to 0.067, and Rv remained unchanged, averaging 0.013 and 0.015 for control and hypoxic conditions, respectively. The changes in vascular resistance observed in alveolar hypoxia appear to be confined to blood vessels that are probably located in larger preseptal blood vessels. KF,C increased significantly from 0.092 to 0.179 ml . min-1 . cmH2O-1 . 100 g lung-1 during hypoxia. Either the surface area available for fluid exchange or the vascular permeability increases with alveolar hypoxia in the isolated dog lung. Inasmuch as vascular pressures were maintained constant in the present study, then the increase in KF,C with alveolar hypoxia is probably associated with changes in vascular permeability rather than an increased surface area of the fluid exchange vessels.
在给离体犬肺通气95% O₂ - 5% CO₂ 时以及在通过95% N₂ - 5% CO₂ 气体混合物通气模拟的肺泡低氧期间，测定等重力毛细血管压力（Pci）以及毛细血管前（Ra）和毛细血管后（Rv）肺血管阻力。此外，在肺泡低氧期间测量滤过系数（KF,C），并与低氧前的测量值进行比较。当在肺泡低氧期间动脉压和静脉压均保持恒定时，Pci从8 mmHg降至6.9 mmHg，总肺血管阻力从0.040（cmH₂O·ml⁻¹·min·100 g肺）增加至0.083。Ra从0.027显著增加至0.067，而Rv保持不变，对照和低氧条件下的平均值分别为0.013和0.015。在肺泡低氧时观察到的血管阻力变化似乎局限于可能位于较大的隔前血管中的血管。在低氧期间，KF,C从0.092显著增加至0.179 ml·min⁻¹·cmH₂O⁻¹·100 g肺⁻¹。在离体犬肺中，随着肺泡低氧，可用于液体交换的表面积或血管通透性增加。由于在本研究中血管压力保持恒定，因此随着肺泡低氧KF,C的增加可能与血管通透性的变化有关，而不是与液体交换血管的表面积增加有关。
