Electron microscopic observations on the morphogenesis of the albino rat lung, with special reference to pulmonary epithelial cells.
Electron microscopic observations on the morphogenesis of the albino rat lung, with special reference to pulmonary epithelial cells.
复制标题
白化大鼠肺形态发生的电子显微镜观察，特别是肺上皮细胞。
作者：
K. O'hare;M. Sheridan
对发育中的白化大鼠肺进行的电子显微镜观察为I型和II型肺上皮细胞的内胚层起源以及间质肺细胞的中胚层起源提供了进一步的证据。
在妊娠第16天到第20天，胎儿内胚层细胞中的细胞质糖原增加。进一步发育显示，在分化的肺上皮细胞中这种物质减少，而在中胚层间质肺细胞中同时增加，这些细胞以前以其高脂质含量为特征。从妊娠第16天到出生后第3天，连续的基底膜勾勒出发育中的大鼠肺的中胚层和内胚层成分。在同一妊娠期内，相邻内胚层上皮细胞之间存在紧密连接。II型肺上皮细胞特有的板层小体可能与大量细胞质糖原同时被发现。这一特征被认为是胎儿内胚层成分的特征。
从内胚层柱状上皮细胞到定型的I型和II型肺上皮细胞，可以追踪到超微结构变化的明确连续性。对中胚层成分的类似观察显示出向成熟间质肺细胞发展的过程。
Electron microscopic observations of developing albino rat lung provide further evidence for the endodermal origin of the type I and II pulmonary epithelial cells, and for the mesodermal origin of the interstitial pulmonary cells.
Cytoplasmic glycogen increased in the fetal endodermal cells from day 16 to the twentieth day of gestation. Further development revealed a decrease of this substance in the differentiating pulmonary epithelial cells, and a concurrent increase in the mesodermal interstitial pulmonary cells, these being cells formerly characterized by their high lipid content. A continuous basement membrane delineated the mesodermal and endodermal components of the developing rat lung from day 16 to the third postnatal day. Tight junctions between adjacent endodermal epithelial cells were present throughout this same gestational period. Lamellar bodies, which are characteristic of the type II pulmonary epithelial cell, may be found simultaneously with large quantities of cytoplasmic glycogen. This feature is considered characteristic of fetal endodermal components.
A definite continuum of ultrastructural changes may be traced from the endodermal, columnar epithelial cells to the definitive type I and II pulmonary epithelial cells. Comparable observations for the mesodermal components reveal a progression leading to mature interstitial pulmonary cells.