THE FUNCTIONS OF PULMONARY EPITHELIAL CELLS AND THEIR SECRETIONS

虽然细支气管Clara细胞的功能尚不清楚， 一般认为细胞是分泌性的。 使用分离的Clara细胞 从兔子的肺中，我们已经表明， 支气管Clara细胞是一种低分子量蛋白， 和子宫珠蛋白的组成相似，子宫珠蛋白是子宫内膜的主要分泌蛋白， 子宫上皮 此外，我们还鉴定了 支气管和气管上皮细胞含有克拉拉细胞分泌 蛋白质，使用免疫金程序。 大部分分泌蛋白 似乎定位于克拉拉细胞的分泌颗粒， 大量位于内质网中。 低 分子量蛋白质似乎由三种主要的同种型组成， 等电点不同。 这些分泌产物 用于研究大鼠气道上皮的分化， 家兔 分泌功能的分化发生在出生后， 种，并与细胞质颗粒的外观。

The functions of the bronchiolar Clara cell are not known although it is generally believed that the cell is secretory. Using Clara cells isolated from the lungs of rabbits we have shown that the major protein secreted by bronchiolar Clara cells is a low molecular weight protein immunochemically and compositionally similar to uteroglobin, the major secretory protein of the uterine epithelium. In addition, we have identified cells of the bronchiolar and tracheal epithelium that contain the Clara cell secretory protein by using an immunogold procedure. Most of the secretory protein appears to be localized in the secretory granules of Clara cells although substantial amounts are located in the endoplasmic reticulum. The low molecular weight protein appears to consist of three major isoforms that differ in their isoelectric points. These secretory products have been used to study the differentiation of the airway epithelium in rats and rabbits. Differentiation of secretory function occurs postnatally in both species and is associated with the appearance of cytoplasmic granules.