Lichey J, Friedrich T, Franke J, Nigam S, Priesnitz M, Oeff K
J Appl Physiol Respir Environ Exerc Physiol. 1984 Oct;57(4):1039-44. doi: 10.1152/jappl.1984.57.4.1039.
The aim of this study was, first, to examine pressure effects of platelet-activating factor (PAF) on pulmonary vasculature and bronchi in isolated perfused and ventilated rat lungs and, second, to investigate pulmonary uptake of tritium-labeled PAF injected into the pulmonary artery. Four different perfusates were used: Krebs-Ringer solution (KRS) and KRS with 0.2, 2.0, and 4% albumin. In the KRS, perfusion and inflation pressure increased by 100 and 47%, respectively, after 100 micrograms PAF. By increasing the albumin concentration, the pressure effects were reduced significantly (P less than 0.01). These changes were paralleled by increasing tritium outflow rates (15.9 +/- 3.6, 49.7 +/- 12.5, 78.3 +/- 8.7, 87.8 +/- 2.6%, respectively). Comparable changes in tritium outflow rates (19.2 +/- 3.9, 38.2 +/- 7.2%) occurred when tracer amounts of labeled PAF were injected, but, in KRS with 2.0 and 4.0% albumin, tritium outflow was significantly lower (52.8 +/- 8.0 and 60.8 +/- 11.8%, respectively). Pressure effects are related to extraction rates. Both pressure effects and extraction rates depend on binding to the albumin in the perfusion medium used. PAF might act on smooth muscle tissue of the pulmonary vasculature. Inflation pressure increases are probably due to concomitant occurrence of edema.
本研究的目的，其一，是检测血小板活化因子（PAF）对离体灌注和通气大鼠肺脏的肺血管和支气管的压力效应；其二，是研究注入肺动脉的氚标记PAF的肺摄取情况。使用了四种不同的灌注液： Krebs-Ringer溶液（KRS）以及含0.2%、2.0%和4%白蛋白的KRS。在KRS中，注入100微克PAF后，灌注压和充气压力分别升高了100%和47%。通过提高白蛋白浓度，压力效应显著降低（P<0.01）。这些变化与氚流出率的增加平行（分别为15.9±3.6%、49.7±12.5%、78.3±8.7%、87.8±2.6%）。注入微量标记PAF时，氚流出率也出现了类似变化（19.2±3.9%、38.2±7.2%），但在含2.0%和4.0%白蛋白的KRS中，氚流出率显著更低（分别为52.8±8.0%和60.8±11.8%）。压力效应与提取率相关。压力效应和提取率均取决于与所用灌注介质中白蛋白的结合。PAF可能作用于肺血管的平滑肌组织。充气压力升高可能是由于同时出现了水肿。
