Chevalier P A, Reed J H, Vandenberg R A, Wood E H
Aviat Space Environ Med. 1978 Jun;49(6):768-78.
Vertical distribution of pulmonary blood flow (VDPBF) was studied, using radioactive microsphere emboli, in dogs without thoracotomy in the right decubitus position during exposure to lateral (--Gy) accelerations of 1, 2, 4, and 6 G. At all levels of force environment studied, an inverse linear relationship was observed between vertical height in the thorax and pulmonary blood flow (ml/min/ml lung tissue) with a decrease in flow to the most dependent region of the lung despite large increases in intravascular pressures at this site. Changes in blood flow were smallest at the mid-lung level, the hydrostatic "balance point" for vascular and pleural pressures. These force environment-dependent changes in VDPBF are not readily explainable by the Starling resistor analog. Gravity-dependent regional differences in pleural and associated interstitial pressures, plus possible changes in vascular tone resulting from inadequate aeration of blood in the most dependent regions of the lung, probably also affect VDPBF.
在右侧卧位且未开胸的犬中，使用放射性微球栓子研究了在1、2、4和6 G的侧向（--Gy）加速度作用下肺血流的垂直分布（VDPBF）。在所研究的所有力环境水平下，观察到胸部垂直高度与肺血流（毫升/分钟/毫升肺组织）之间呈反线性关系，尽管该部位血管内压力大幅升高，但肺最下垂区域的血流仍减少。肺中部水平（血管和胸膜压力的流体静力“平衡点”）的血流变化最小。VDPBF中这些与力环境相关的变化难以用斯塔林电阻器模型来解释。胸膜和相关间质压力的重力依赖性区域差异，以及肺最下垂区域血液通气不足可能导致的血管张力变化，可能也会影响VDPBF。
