Pulmonary Interstitial Mechanics

肺间质是排出肺微血管滤液的通道。因此，其性质对了解正常体液平衡的维持和肺水肿的发病机制具有重要意义。间隙液的清除取决于静水压力差异引起的体积流动和蛋白质浓度差异引起的渗透流动。在以前的研究中，测定了水合作用、蛋白质浓度、流体粘度、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在白蛋白和透明质酸溶液中空间排斥所预期的相反。最近的研究表明，白蛋白的间质筛分和有限反射系数在正常水合作用下低浓度时增加，与白蛋白的自由扩散有关。这种膜样性质与通常分配给间质的溶液的性质相反。一个主要的目标是描述间质在其膜性质方面。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降低扩散反应的影响。在液体充气肺间质袖口生长过程中白蛋白浓度的纵向梯度研究将支持稳态流动中在间质节段测量的筛分行为。这些研究将测量从小动脉到大血管的血管间质袖口白蛋白的空间排斥。

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.