Li J, Lai-Fook S J
Center for Biomedical Engineering, University of Kentucky, Lexington 40506-0070.
Respir Physiol. 1992 Aug;89(2):133-46. doi: 10.1016/0034-5687(92)90045-x.
The response in perivascular interstitial pressure to water accumulation was measured in air-inflated isolated rabbit lungs. The blood vessels and trachea of isolated lungs were cannulated and the vascular cannulas were connected to a reservoir filled either with a 3% albumin in saline solution (control) or with hyaluronidase in the albumin solution (treated). The lungs were inflated to 5 cmH2O transpulmonary pressure and the vascular reservoir elevated to a height of 7-10 cm above the lung base. The reservoir was suspended by a load cell which measured liquid accumulation in the lung. As the lung gained weight, interstitial pressure was measured by the micropuncture technique in the interstitium surrounding a vein near the hilum of an upper lobe. In control lungs, interstitial pressure increased monotonically with time from a value slightly below 0 cmH2O (pleural pressure) to a value of approx. 3.0 cmH2O by 5 h. In treated lungs, interstitial pressure increased more slowly to a value of approx. 1.5 cmH2O by 5 h. Interstitial compliance, the change in weight gain divided by the change in interstitial pressure, was 1.2 g.(g lobe wt)-1.cmH2O-1 for the control lungs and 2.9 for the treated lungs. A two-compartment electrical analog model representing the perivascular interstitium and alveolar liquid space was developed to simulate the data. The analysis indicated that in the control lungs, perivascular interstitial conductance and compliance were 5-fold and 15-fold smaller than those of the alveolar liquid space, respectively. The slower rise in interstitial pressure with water accumulation in the treated lungs was attributed to an increased compliance of the alveolar liquid space. The effect of hyaluronidase on the alveolar liquid space was to increase its compliance 2.4-fold with little change in its fluid resistance.
在空气充盈的离体兔肺中测量血管周围间质压力对水蓄积的反应。将离体肺的血管和气管插管，血管插管连接到一个储液器，该储液器要么装有含3%白蛋白的盐溶液（对照），要么装有白蛋白溶液中的透明质酸酶（处理组）。将肺充气至5 cmH₂O的跨肺压，并将血管储液器升高至肺底部上方7 - 10 cm的高度。储液器由一个称重传感器悬挂，该传感器测量肺内的液体蓄积。随着肺重量增加，通过微穿刺技术在上叶肺门附近静脉周围的间质中测量间质压力。在对照肺中，间质压力随时间从略低于0 cmH₂O（胸膜压力）的值单调增加，到5小时时达到约3.0 cmH₂O的值。在处理组肺中，间质压力增加较慢，到5小时时达到约1.5 cmH₂O的值。间质顺应性，即体重增加的变化除以间质压力的变化，对照肺为1.2 g·(g肺叶重量)⁻¹·cmH₂O⁻¹，处理组肺为2.9。开发了一个双室电模拟模型来代表血管周围间质和肺泡液体空间，以模拟数据。分析表明，在对照肺中，血管周围间质传导率和顺应性分别比肺泡液体空间小5倍和15倍。处理组肺中随着水蓄积间质压力上升较慢归因于肺泡液体空间顺应性增加。透明质酸酶对肺泡液体空间的作用是使其顺应性增加2.4倍，而其液体阻力变化很小。
