Zelter M, Lipavsky A, Hoeffel J M, Murray J F
J Appl Physiol Respir Environ Exerc Physiol. 1984 Jun;56(6):1512-20. doi: 10.1152/jappl.1984.56.6.1512.
To determine whether [14C]urea permeability-surface area product (PS) is a reliable indicator of changes in permeability in various injuries and its relationship to indicator-dilution and gravimetric lung water contents, we studied six groups of anesthetized, paralyzed, and mechanically ventilated dogs (5 animals each). The groups consisted of control dogs, those injured by intravenous alloxan, oleic acid, or glass beads, and those exposed to acute hypoxia or increased left atrial pressure from volume loading (Pla). Interanimal variation of PS was large (3.0-15.0 ml/s), but successive hourly values in individual animals were stable for 2 h in experimental groups and for 4 h in controls. The PS increased after alloxan, elevated Pla, and 2 h of hypoxia; PS decreased after oleic acid and microemboli. The gravimetric lung water increased after alloxan, oleic acid, and microemboli, and indicator-dilution lung water increased only after alloxan. We conclude 1) that intersubject variability requires normalization to enable detection of significant deviation from base line, and 2) that decreased PS after oleic acid and microvascular injury occurred because vascular obstruction, which decreased surface area, masked probable coexisting increases in capillary permeability.
为了确定[14C]尿素通透面积乘积（PS）是否是各种损伤中通透性变化的可靠指标，以及它与指示剂稀释法和重量法测定的肺含水量之间的关系，我们研究了六组麻醉、麻痹并机械通气的犬（每组5只）。这些组包括对照犬、静脉注射四氧嘧啶、油酸或玻璃珠致伤的犬，以及急性缺氧或容量负荷致左心房压力升高（Pla）的犬。PS的动物间差异很大（3.0 - 15.0 ml/s），但在实验组中，个体动物连续每小时的值在2小时内保持稳定，在对照组中则在4小时内保持稳定。四氧嘧啶、Pla升高及缺氧2小时后PS升高；油酸和微栓子后PS降低。四氧嘧啶、油酸和微栓子后重量法测定的肺含水量增加，指示剂稀释法测定的肺含水量仅在四氧嘧啶后增加。我们得出结论：1）个体间的变异性需要进行标准化，以便能够检测到与基线的显著偏差；2）油酸和微血管损伤后PS降低是因为血管阻塞减少了表面积，掩盖了可能同时存在的毛细血管通透性增加。
