Harris T R, Roselli R J, Maurer C R, Parker R E, Pou N A
J Appl Physiol (1985). 1987 May;62(5):1852-9. doi: 10.1152/jappl.1987.62.5.1852.
The purpose of these studies was a comparison of [14C]urea (U) and 1,3-[14C]propanediol (Pr) as measures of lung vascular permeability-surface area (PS) under base-line conditions and after lung injury caused by alloxan infusion in isolated perfused dog lungs. Indicator mixtures of 125I-albumin, 51Cr-red blood cells, 3HOH, and U or Pr were injected under base-line conditions, after 1.2 g of alloxan, and after an additional 0.8 g of alloxan. Indicator-dilution curves were analyzed from sampled outflow blood to provide PS, the square root of effective extravascular diffusivity multiplied by exchange surface area (D1/2S), and extravascular lung water (EVLW) from the tracer mean transit times (VW). Results show that alloxan increases PS and D1/2S for U, D1/2S for Pr, and VW and EVLW by desiccation. All indicator-dilution parameters correlate significantly with alloxan dose. Interpretation of Pr transport suggests that materials with lipid and hydrophilic pathways might be used in conjunction with U to minimize the effects of surface area changes and increase the sensitivity of these tracers to permeability alteration. In addition Pr may be a useful alternative to U as a marker of vascular damage.
这些研究的目的是比较[14C]尿素（U）和1,3-[14C]丙二醇（Pr），以此作为在基线条件下以及在给离体灌注犬肺输注四氧嘧啶所致肺损伤后肺血管通透性-表面积（PS）的测量指标。在基线条件下、注射1.2 g四氧嘧啶后以及再注射0.8 g四氧嘧啶后，分别注入125I-白蛋白、51Cr-红细胞、3HOH以及U或Pr的指示剂混合物。对采集的流出血液中的指示剂稀释曲线进行分析，以提供PS、有效血管外扩散率乘以交换表面积的平方根（D1/2S）以及根据示踪剂平均通过时间（VW）得出的血管外肺水（EVLW）。结果显示，四氧嘧啶会使U的PS和D1/2S、Pr的D1/2S以及VW和EVLW因干燥作用而增加。所有指示剂稀释参数均与四氧嘧啶剂量显著相关。对Pr转运的解读表明，具有脂质和亲水途径的物质可与U联合使用，以尽量减少表面积变化的影响，并提高这些示踪剂对通透性改变的敏感性。此外，Pr可能是一种有用的替代U的血管损伤标志物。
