ALVEOLAR LINING LAYER IS THIN AND CONTINUOUS - LOW-TEMPERATURE SCANNING ELECTRON-MICROSCOPY OF RAT LUNG
ALVEOLAR LINING LAYER IS THIN AND CONTINUOUS - LOW-TEMPERATURE SCANNING ELECTRON-MICROSCOPY OF RAT LUNG
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DOI：
10.1152/jappl.1995.79.5.1615
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发表时间：
1995-11-01
影响因子：
3.3
通讯作者：
CLEMENTS, JA
中科院分区：
文献类型：
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作者：
BASTACKY, J;LEE, CYC;CLEMENTS, JA
低温电子显微镜在液氮温度下将含水结构保持为固体水，用于对麻醉大鼠在15 cm H（2）O透肺压下冷冻的充满空气的肺的肺泡衬里层（包括表面活性剂及其含水亚相）进行成像。在最外侧胸膜下肺泡壁的横向骨折处测量内衬层厚度，该壁可以用金属镜冷冻固定以足以将冰晶生长限制在10 nm并防止明显的水运动的速率固化。对于0.2 μ m的面积加权平均厚度，在肺泡壁的相对平坦部分上的液体层厚度平均为0.14 μ m，在肺泡壁连接处的液体层厚度平均为0.89 μ m，在突出特征上的液体层厚度平均为0.09 μ m（9只大鼠，20个壁，16个连接处和146个区域）。肺泡衬里层呈现连续的、浸没的上皮细胞微绒毛和细胞间连接脊;厚度从几纳米到几微米不等;并且用于使充气至区1或2条件的肺中的肺泡气液界面平滑。
The low-temperature electron microscope, which preserves aqueous structures as solid water at liquid nitrogen temperature, was used to image the alveolar lining layer, including surfactant and its aqueous subphase, of air-filled lungs frozen in anesthetized rats at 15-cmH(2)O transpulmonary pressure. Lining layer thickness was measured on cross fractures of walls of the outermost subpleural alveoli that could be solidified with metal mirror cryofixation at rates sufficient to limit ice crystal growth to 10 nm and prevent appreciable water movement. The thickness of the liquid layer averaged 0.14 mu m over relatively flat portions of the alveolar walls, 0.89 mu m at the alveolar wall junctions, and 0.09 mu m over the protruding features (9 rats, 20 walls, 16 junctions, and 146 areas), for an area-weighted average thickness of 0.2 mu m. The alveolar lining layer appears continuous, submerging epithelial cell microvilli and intercellular junctional ridges; varies from a few nanometers to several micrometers in thickness; and serves to smooth the alveolar air-liquid interface in lungs inflated to zone 1 or 2 conditions.