Fehrenbach H, Schmiedl A, Wahlers T, Hirt S W, Brasch F, Riemann D, Richter J
Abteilung Elektronenmikroskopie, Universität Göttingen, Germany.
Anat Rec. 1995 Sep;243(1):49-62. doi: 10.1002/ar.1092430107.
Pulmonary type II pneumocytes have been examined by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and morphometry in numerous mammals. Until now, the fine structure of the human type II pneumocyte has not been studied by means of morphometry.
Eleven human donor lungs, which could not be made available for a suitable recipient, were preserved with Euro Collins solution (ECS) according to clinical organ preservation techniques. The lungs were fixed via the airways. Systematic random samples were analyzed by SEM, TEM, and classical stereological methods.
Type II pneumocytes showed normal fine structural characteristics. Morphometry revealed that although inter-individual variation due to some oedematous swelling was present, the cells were in a normal size range as indicated by an estimated mean volume of 763 +/- 64 microns 3. The volume densities were: nucleus 21.9 +/- 2.2%, mitochondria 5.8 +/- 0.9%, lamellar bodies 9.8 +/- 3.6%, and remaining cytoplasmic components 62.4 +/- 2.9% of the cell volume. Since the inter-individual variations in the volume densities referred to the cell may, to variable degrees, reflect the variation in the reference space, the volume densities referred to the constant test point system and the respective volume-to-surface ratios were used for inter-individual comparisons. These parameters indicate that lamellar bodies were independent of cellular swelling, while mitochondria < nucleus < remaining cytoplasmic components increased in size with increasing cell size.
Two to 7.5 hours of cold ischemia following ECS preservation do not deteriorate the fine structure of type II pneumocytes of human donor lungs. For reliable assessment of fine structural variations, morphometric parameters are required that are independent of variations in cell size.
众多哺乳动物的肺Ⅱ型上皮细胞已通过扫描电子显微镜（SEM）、透射电子显微镜（TEM）及形态测量学进行了研究。迄今为止，尚未通过形态测量学方法对人Ⅱ型上皮细胞的精细结构进行研究。
根据临床器官保存技术，用欧洲柯林斯溶液（ECS）保存11个无法用于合适受体的人类供体肺。通过气道对肺进行固定。采用SEM、TEM和经典体视学方法对系统随机样本进行分析。
Ⅱ型上皮细胞呈现出正常的精细结构特征。形态测量学显示，尽管存在因一些水肿性肿胀导致的个体间差异，但细胞处于正常大小范围内，估计平均体积为763±64立方微米。体积密度分别为：细胞核21.9±2.2%，线粒体5.8±0.9%，板层小体9.8±3.6%，其余细胞质成分占细胞体积的62.4±2.9%。由于细胞体积密度的个体间差异可能在不同程度上反映参考空间的变化，因此采用参考恒定测试点系统的体积密度和各自的体积与表面积比进行个体间比较。这些参数表明，板层小体与细胞肿胀无关，而线粒体<细胞核<其余细胞质成分随细胞大小增加而增大。
ECS保存后2至7.5小时的冷缺血不会使人类供体肺Ⅱ型上皮细胞的精细结构恶化。为可靠评估精细结构变化，需要不受细胞大小变化影响的形态测量参数。
