Gillett D, Ford G T, Anthonisen N R
J Appl Physiol Respir Environ Exerc Physiol. 1981 Dec;51(6):1457-62. doi: 10.1152/jappl.1981.51.6.1457.
We froze 10 isolated canine lower lobes by immersing them in chlorothene (sp gr 1.4) at -20 degrees C. In six instances the contralateral lower lobe was frozen over dry ice. The lobes were then sliced horizontally, and the volume and weight of each slice were measured so that expansion (specific volume) and the amount of tissue (weight) could be assessed as a function of distance down the lung. Lobes frozen under chlorothene at low [35% total lung capacity (TLC)] and medium [60% TLC] volumes demonstrated a gradient of regional expansion that was about half that predicted on the basis of pleural surface pressure. Lobes frozen under chlorothene at high volumes [80% TLC] did not demonstrate a significant gradient of regional expansion. These results demonstrated tissue interdependence. When lobes frozen under chlorothene were compared with contralateral lobes frozen over dry ice, substantial differences in shape were evident. Chlorothene-frozen lobes had greater vertical height, and a smaller fraction of their weight was present in dependent regions: lobes frozen in chlorothene had half as much tissue over the lower 40% of their vertical height as did lobes frozen over dry ice. We demonstrated two mechanisms by which relative homogeneity of regional expansion was maintained in response to differences in pleural pressure, tissue interdependence and tissue movement from more compressed to less compressed regions.
我们将10个分离的犬类下叶在-20摄氏度下浸入氯乙烯（比重1.4）中进行冷冻。在6个实例中，对侧下叶在干冰上进行冷冻。然后将这些肺叶水平切片，并测量每一片的体积和重量，以便能够根据肺内深度评估膨胀情况（比容）和组织量（重量）。在低肺容量[35%肺总量（TLC）]和中肺容量[60% TLC]下于氯乙烯中冷冻的肺叶显示出区域膨胀梯度，该梯度约为根据胸膜表面压力预测值的一半。在高肺容量[80% TLC]下于氯乙烯中冷冻的肺叶未显示出明显的区域膨胀梯度。这些结果证明了组织间的相互依存关系。当将在氯乙烯中冷冻的肺叶与在干冰上冷冻的对侧肺叶进行比较时，形状上的显著差异很明显。在氯乙烯中冷冻的肺叶垂直高度更大，且其重量在下垂区域所占比例更小：在氯乙烯中冷冻的肺叶在其垂直高度的下40%范围内的组织量只有在干冰上冷冻的肺叶的一半。我们证明了两种机制，通过这两种机制，针对胸膜压力差异、组织相互依存关系以及组织从压缩程度较高区域向压缩程度较低区域的移动，区域膨胀的相对均匀性得以维持。
