Parker James C, Townsley Mary I
Department of Physiology and Center for Lung Biology, College of Medicine, University of South Alabama, Mobile, Alabama 36688, USA.
Am J Physiol Lung Cell Mol Physiol. 2008 Aug;295(2):L235-7. doi: 10.1152/ajplung.00064.2008. Epub 2008 May 23.
Current emphasis on translational application of genetic models of lung disease has renewed interest in the measurement of the gravimetric filtration coefficient (K(f)) as a means to assess vascular permeability changes in isolated perfused lungs. The K(f) is the product of the hydraulic conductivity and the filtration surface area, and is a sensitive measure of vascular fluid permeability when the pulmonary vessels are fully recruited and perfused. We have observed a remarkable consistency of the normalized baseline K(f) values between species with widely varying body weights from mice to sheep. Uniformity of K(f) values can be attributed to the thin alveolar capillary barrier required for gas exchange and the conserved matching of lung vascular surface area to the oxygen requirements of the body mass. An allometric correlation between the total lung filtration coefficient (K(f,t)) and body weight in several species (r(2)=1.00) had a slope that was similar to those reported for alveolar and pulmonary capillary surface areas and pulmonary diffusion coefficients determined by morphometric methods in these species. A consistent K(f) is dependent on accurately separating the filtration and vascular volume components of lung weight gain, then K(f) is a consistent and repeatable index of lung vascular permeability.
当前对肺部疾病遗传模型转化应用的重视，重新激发了人们对重量过滤系数（K(f)）测量的兴趣，以此作为评估离体灌流肺血管通透性变化的一种手段。K(f)是水力传导率与过滤表面积的乘积，当肺血管充分募集和灌注时，它是血管液体通透性的敏感指标。我们观察到，从小鼠到绵羊，体重差异很大的不同物种之间，标准化基线K(f)值具有显著的一致性。K(f)值的一致性可归因于气体交换所需的薄肺泡毛细血管屏障，以及肺血管表面积与体重氧需求的保守匹配。几种物种的全肺过滤系数（K(f,t)）与体重之间的异速生长相关性（r(2)=1.00），其斜率与这些物种通过形态计量学方法测定的肺泡和肺毛细血管表面积以及肺扩散系数所报告的斜率相似。一致的K(f)取决于准确分离肺重量增加中的过滤和血管容积成分，那么K(f)就是肺血管通透性的一个一致且可重复的指标。
