Pulmonary Interstitial Mechanics

肺动脉是从肺排出微血管滤液的途径。因此，其性质对于理解如何维持正常的液体平衡和肺水肿的发病机制是重要的。间质液的清除取决于由静水压力差异引起的整体流量和由蛋白质浓度差异引起的渗透流量。在先前的研究中，测量了水合作用、蛋白质浓度、液体粘度、电荷和透明质酸酶对间质电导率的影响。白蛋白和透明质酸酶的作用与白蛋白和透明质酸溶液中空间排阻的预期作用相反。最近的研究表明，白蛋白的间质筛分和有限的反射系数，在低浓度下增加与正常水合作用，结合白蛋白的自由扩散。这种膜状性质与通常分配给氚的溶液的性质相反。一个主要的目标是描述氚在其膜性能。将研究透明质酸酶对白蛋白间质筛分的影响以及水合作用对透明质酸酶扩散反应降低的影响。稳态血流期间在间质段中测量的筛分行为将得到液体充盈肺间质袖增长期间白蛋白浓度纵向梯度研究的支持。这些研究将测量从小动脉到大血管的血管间质袖中白蛋白的空间排阻。

The pulmonary interstitium is a pathway that drains microvascular filtrate from the lung. Thus its properties are important to the understanding how normal fluid balance is maintained and the pathogenesis of pulmonary edema. The clearance of interstitial fluid depends on bulk flow caused by differences in hydrostatic pressure and osmotic flow caused by differences in protein concentration. In previous studies, the effects of hydration, protein concentration, fluid viscosity, electric charge, and hyaluronidase on interstitial conductivity were measured. The effects of albumin and hyaluronidase were opposite to those expected from steric exclusion in solutions of albumin and hyaluronan. Recent studies indicated interstitial sieving of albumin and a finite reflection coefficient that increased at low concentrations with normal hydration, in conjunction with free diffusion of albumin. Such a membrane-like property is opposite to the properties of solutions usually assigned to interstitium. A major goal is to describe the interstitium in terms of its membrane properties. The effect of hyaluronidase on interstitial sieving of albumin and the effect of hydration on the reduced diffusive response to hyaluronidase will be studied. The sieving behavior measured in interstitial segments during steady state flow will be supported by studies of the longitudinal gradient in albumin concentration during interstitial cuff growth in liquid-inflated .lungs. These studies will measure steric exclusion of albumin in interstitial cuffs of vessels ranging from arterioles to large vessels.