Nicolaysen G, Hauge A
J Appl Physiol Respir Environ Exerc Physiol. 1980 Feb;48(2):256-64. doi: 10.1152/jappl.1980.48.2.256.
We studied the fluid shifts in isolated, plasma-perfused rabbit lungs kept completely within zone I. The rate of fluid filtration or reabsorption was determined gravimetrically. A rise in alveolar pressure at constant pleural and vascular pressures reduced th rate of filtration or increased the rate of reabsorption in seven of eight lungs. In seven of seven lungs a reduction in pleural pressure at constant alveolar and vascular pressures increased the rate of filtration or decreased the rate of reabsorption. Thus, a given rise in lung volume had opposite effects depending on whether this rise was caused by an increased alveolar or reduced pleural pressure. Therefore, the exchange vessels studied cannot be true extra-alveolar vessels, which always expand (reflecting a rise in transmural pressure) with a rise in lung volume. When alveolar and pleural pressures were equally increased at constant vascular pressure, the rate of filtration was reduced in four of four lungs. The results can be explained through the existence of exchange vessels situated neither in the alveolar septae proper nor among the true extra-alveolar vessels. The vessels in the alveolar junctions are the most likely candidates.
我们研究了完全处于I区的离体、血浆灌注兔肺中的液体转移情况。通过重量法测定液体滤过或重吸收的速率。在恒定的胸膜和血管压力下，肺泡压力升高会降低八只肺中七只的滤过速率或增加重吸收速率。在七只肺中的七只中，在恒定的肺泡和血管压力下，胸膜压力降低会增加滤过速率或降低重吸收速率。因此，肺容积的给定增加会产生相反的效果，这取决于这种增加是由肺泡压力升高还是胸膜压力降低引起的。因此，所研究的交换血管不可能是真正的肺泡外血管，因为随着肺容积增加，真正的肺泡外血管总是扩张（反映跨壁压力升高）。当在恒定的血管压力下肺泡和胸膜压力同等增加时，四只肺中的四只滤过速率降低。这些结果可以通过既不存在于肺泡间隔本身也不存在于真正的肺泡外血管之间的交换血管的存在来解释。肺泡连接处的血管是最有可能的候选者。
