PLEURAL LIQUID EXCHANGE AND LUNG MECHANICS

本研究的目的是研究一些机械因素 影响胸膜压力，因为它们与局部肺容量有关 分配和胸膜液体交换。局部肺部容量 分布对于理解导致 最佳气体交换 影响胸水交换的因素有 对认识胸膜炎的病因和发病机制具有重要意义 胸腔积液和胸膜表面的有效润滑。 的 该建议的第一部分涉及胸膜液的测量 压力作为局部肺容量的反映。 的因素 负责不同身体的垂直胸膜压力梯度 位置将在实验和理论上进行检查。 在 麻醉动物，肺膨胀对局部肺的影响 在不同的身体位置膨胀将使用两个测量 技术：使用肋骨囊测量胸膜液体压力 通过胸膜窗测量肺泡大小， 视频显微镜 胸壁并置区的胸膜压 将使用FIB胶囊测量隔膜到胸腔。 的影响 身体位置和加速度对局部肺扩张的影响 用肺、胸壁和腹部的有限元模型进行研究。 胸膜压梯度的预测值将与 试验结果 该建议的第二部分涉及 胸膜腔内和通过胸膜腔的胸膜液体的运动。 胸膜液体压力由胸膜表面压力控制， 这是肺、胸壁和重力相互作用的结果。 因此 胸膜液体压力的垂直梯度小于 流体静力学，导致胸膜液体的净向下粘性流动。 在稳定状态下，胸膜液体交换率等于粘性 流量，其是胸膜腔厚度的函数。 的影响 心源性运动和通气对胸水运动的影响 将通过注射荧光微球和荧光 液体进入胸膜腔，并遵循的运动， 荧光染料通过视频显微镜。 高血压的影响 胸膜毛细血管滤过将通过测量 自发性高血压大鼠（SHR）胸膜微血管压 微穿刺和滤过率由放射性的运动 血液中的白蛋白进入胸膜腔

The goal of this research is to study some of the mechanical factors affecting pleural pressure as they pertain to regional lung volume distribution and pleural liquid exchange. Regional lung volume distfibution is important to understanding the factors responsible for optimal gas exchange. The factors affecting pleural liquid exchange are important to understanding the etiology and pathogenesis of pleural effusions and to the efficient lubrication of the pleural surfaces. The first part of this proposal concerns the measurement of pleural liquid pressure as a reflection of regional lung volume. The factors responsible for the vertical-pleural pressure gradient in different body positions will be examined both experimentally and theoretically. In anesthetized animals, the effect of lung inflation on the regional lung expansion in different body positions will be measured using two techniques: measurement of pleural liquid pressure using rib capsules and measurement of alveolar size through pleural windows via videomicroscopy. Pleural pressure in the zone of apposition of the diaphragm to rib cage will be measured using fib capsules. The effects of body position and acceleration on regional lung expansion will be studied with a finite element model of the lung, chest wall and abdomen. Predictions of the pleural pressure gradient will be compared to experimental results. The second part of this proposal concerns the movement of pleural liquid within and through the pleural space. Pleural liquid pressure is governed by pleural surface pressure, the result of the interaction among the lung, chest wall and gravity. Thus the vertical gradient in pleural liquid pressure is less than hydrostatic, resuking in a net downward viscous flow of pleural liquid. In the steady state pleural liquid exchange rate equals the viscous flow, which is a function of the pleural space thickness. The effect of cardiogenic motion and ventilation on the movement of pleural liquid will be measured by injecting fluorescent microspheres and fluorescent liquid into the pleural space and following the movement of the fluorescent dye via videomicroscopy. The effect of hypertension on pleural capillary filtration will be examined by measuring in spontaneously hypertensive rats (SHR) pleural micmvascular pressure by micropuncture and the filtration rate by the movement of radioactive albumin from the blood into the pleural space.