IDENTIFICATION & CHARACTERIZATION OF MATERIALS SECRETED BY PULMONARY CLARA CELLS

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， 子宫上皮兔气管细胞也分泌子宫珠蛋白 尽管在形态学上气管上皮中没有细胞 与细支气管Clara细胞相同。我们已经确定了气管 上皮细胞含有子宫珠蛋白通过使用免疫金程序。 这些研究表明，含子宫珠蛋白的气管细胞，如 细支气管无纤毛， 内质网然而，与细支气管Clara细胞不同， 气管细胞整体呈高柱状，含少量 分泌颗粒

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 bronchilar Clara cells is a low molecular weight protein immunochemically and compositionally similar to uteroglobin, the major secretory protein of the uterine epithelium. Rabbit tracheal cells also secrete uteroglobin although morphologically there are no cells in the tracheal epithelium identical to bronchiolar Clara cells. We have identified tracheal epithelial cells containing uterglobin by using an immunogold procedure. These investigations reveal that uterglobin-containing tracheal cells, like those of the bronchioles are nonciliated and contain abundant smooth endoplasmic reticulum. However, unlike the bronchiolar Clara cell, the tracheal cell is tall and columnar in overall shape and it contains few secretory granules.