Olson L E, Pou A, Harris T R
Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee 37232.
J Appl Physiol (1985). 1991 Mar;70(3):1085-96. doi: 10.1152/jappl.1991.70.3.1085.
A combination of an amphipathic-indicator-dilution (ID) diffusing tracer 1,4[14C]butanediol (B) and a hydrophilic tracer ([14C]urea) (U) was hypothesized to provide a capillary surface area- (S) independent assessment of lung microvascular permeability (P). We performed ID studies on isolated perfused dog lungs and administered randomly two interventions, increasing P by alloxan infusion and reduction in S by lobar ligation. The ratio of PS product of U (PSU) to that for butanediol (PSB) was sensitive to changes in P yet insensitive to changes in S. We performed ID studies in which the dependence of PSU and PSB on flow, hematocrit, and plasma protein binding were examined. Measurements of PSU and PSB after flow and hematocrit were changed suggested that these factors have no significant independent effects. From ID and in vitro studies we also found that no significant binding of B to plasma proteins (albumin) occurred. We concluded that ID techniques using B and U provide a consistent measure of P, despite changes in S, hematocrit, plasma protein concentration, and recruitment.
据推测，一种两亲性指示剂稀释（ID）扩散示踪剂1,4[¹⁴C]丁二醇（B）和亲水性示踪剂（[¹⁴C]尿素）（U）的组合可提供一种独立于毛细血管表面积（S）的肺微血管通透性（P）评估方法。我们对离体灌注的犬肺进行了ID研究，并随机进行了两种干预，即通过注入四氧嘧啶增加P以及通过肺叶结扎减少S。尿素（PSU）与丁二醇（PSB）的PS乘积之比对P的变化敏感，但对S的变化不敏感。我们进行了ID研究，其中考察了PSU和PSB对流量、血细胞比容和血浆蛋白结合的依赖性。在改变流量和血细胞比容后对PSU和PSB的测量表明，这些因素没有显著的独立影响。从ID和体外研究中我们还发现，B与血浆蛋白（白蛋白）没有显著结合。我们得出结论，尽管S、血细胞比容、血浆蛋白浓度和募集发生了变化，但使用B和U的ID技术仍能提供一致的P测量值。
