PULMONARY SURFACTANT - SURFACE-PROPERTIES AND FUNCTION OF ALVEOLAR AND AIRWAY SURFACTANT
PULMONARY SURFACTANT - SURFACE-PROPERTIES AND FUNCTION OF ALVEOLAR AND AIRWAY SURFACTANT
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DOI：
10.1351/pac199264111745
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发表时间：
1992-11-01
影响因子：
1.8
通讯作者：
GEHR, P
中科院分区：
文献类型：
--
作者：
SCHURCH, S;LEE, M;GEHR, P
肺泡气-液界面处的肺表面活性剂膜在肺放气时将表面张力降低至低于1 mN/m的值。除了低而稳定的表面张力之外，由纤维连续体提供的相互依赖性使得肺能够维持有效气体交换所必需的大的肺泡表面积。肺表面活性物质提取物的表面张力-面积关系得到了一个新的装置，其中包含一个可控大小的捕获气泡。在3-4次压缩-扩张循环后，肺泡表面活性剂膜表现出肺泡表面的低表面张力、塌陷率和压缩特性，不仅肺泡而且支气管都被表面活性剂膜覆盖。当吸入的颗粒沉积在气道或肺泡中时，通过表面力朝向它们被保留的上皮移位。Langmuir-Wilhelmy平衡实验表明，肺表面活性剂促进球形乳胶颗粒从空气中向水相的位移。颗粒浸入的程度取决于表面活性膜的表面张力。表面张力越低，颗粒浸入含水亚相中的程度越大。电子显微镜显示，周围气道和肺泡中的颗粒被发现低于表面活性剂膜，并淹没在亚相中。这可能促进巨噬细胞的清除。
The pulmonary surfactant film at the alveolar air-liquid interface reduces the surface tension to a value below 1 mN/m on lung deflation. In addition to a low and stable surface tension, interdependence provided by the fibrous continuum enables the lung to maintain a large alveolar surface area, necessary for an efficient gas exchange. Surface tension-area relations from lung surfactant extracts are obtained with a new apparatus that contains a captive bubble of controllable size. Upon 3-4 compression-expansion cycles, surfactant films exhibit the low surface tensions, collapse rates and compressibilities characteristic of alveolar surfaces.Not only the alveoli but also the bronchi are covered by a surfactant film. Inhaled particles, when deposited in the airways or alveoli, are displaced by surface forces towards the epithelium where they are retained. Experiments in the Langmuir-Wilhelmy balance showed that pulmonary surfactant promotes the displacement of spherical latex particles from air to the aqueous phase. The extent of particle immersion depends on the surface tension of the surface active film. The lower the surface tension, the greater is the immersion of the particles into the aqueous subphase. Electron microscopy demonstrates that particles in peripheral airways and alveoli are found below the surfactant film and submerged in the subphase. This may promote clearance by macrophages.