Bastacky J, Goerke J
Research Medicine and Radiation Biophysics Division, Lawrence Berkeley Laboratory, University of California, Berkeley 94720.
J Appl Physiol (1985). 1992 Jul;73(1):88-95. doi: 10.1152/jappl.1992.73.1.88.
Interalveolar pores of Kohn, small uniform-sized epithelium-lined openings in alveolar walls of normal lung, have historically been demonstrated with electron-microscopic techniques that remove water. We show these pores to be present but almost invariably filled with material when water and surfactant are preserved in frozen hydrated lung examined with low-temperature scanning electron microscopy. In the normal mouse, 16 open empty pores per alveolus were found in instillation-fixed dried lung vs. less than 1 per alveolus in frozen hydrated lungs (P less than 0.001). In the normal rat, 13 pores were seen per alveolus in instillation-fixed dried lung vs. less than 1 per alveolus in frozen hydrated lungs (P less than 0.001). We suggest that pores of Kohn 1) function primarily as conduits for interalveolar movement of alveolar liquid, surfactant components, and macrophages, 2) provide distributed sites for tubular myelin storage without increasing gas diffusion pathway thickness in the alveolar subphase itself, and 3) do not function as pathways for collateral ventilation during normal breathing in the absence of atelectasis or obstruction.
科恩肺泡间孔是正常肺脏肺泡壁上大小均匀、内衬上皮的小孔，历史上一直是通过去除水分的电子显微镜技术来证实其存在的。我们发现，在用低温扫描电子显微镜检查的冷冻水合肺中，当保留水分和表面活性剂时，这些小孔确实存在，但几乎总是充满了物质。在正常小鼠中，滴注固定的干燥肺中每个肺泡有16个开放的空孔，而冷冻水合肺中每个肺泡少于1个（P<0.001）。在正常大鼠中，滴注固定的干燥肺中每个肺泡可见13个孔，而冷冻水合肺中每个肺泡少于1个（P<0.001）。我们认为，科恩孔1）主要作为肺泡液、表面活性剂成分和巨噬细胞在肺泡间移动的通道；2）为管状髓磷脂储存提供分布位点，而不会增加肺泡亚相中气体扩散途径的厚度；3）在没有肺不张或阻塞的正常呼吸过程中，不作为侧支通气的途径。
