Immunocytochemical localization and identification of the major surfactant protein in adult rat lung.
Immunocytochemical localization and identification of the major surfactant protein in adult rat lung.
复制标题
成年大鼠肺中主要表面活性剂蛋白的免疫细胞化学定位和鉴定。
DOI：
10.1177/29.2.7019304
复制
发表时间：
1981
期刊：
影响因子：
--
通讯作者：
B. Benson
中科院分区：
文献类型：
--
作者：
M. Williams;B. Benson
我们研究了72,000道尔顿蛋白肺表面活性物质的细胞和亚细胞代谢部位，以提供对这种富含磷脂的分泌产物的合成、细胞内组装和肺泡内代谢的机制的深入了解。表面活性物质(约90%脂肪，10%蛋白质重量)通过密度梯度离心法纯化。用纯化的材料制备抗血清，通过亲和层析获得特异性抗体。用辣根过氧化物酶标记的Fab在大鼠肺内定位该抗原。该抗体仅标记II型细胞的粗面内质网和高尔基体。II型细胞中的一些多泡小体也被标记，但该抗原是否存在于板层小体中尚不确定。肺泡巨噬细胞的吞噬小体被标记为I型细胞中的类似包涵体。通过间接免疫细胞化学，我们确定肺泡细胞表面的标记并不代表存在连续的分泌型表面活性物质。这些结果表明，只有II型细胞合成表面活性蛋白，然后主要是肺泡巨噬细胞参与其分解代谢。蛋白质与脂类结合的初始细胞内部位可能是先前其他人所提出的多泡小体。
We investigated the cellular and subcellular sites of metabolism of the 72,000 dalton protein of pulmonary surfactant in order to provide insights into mechanisms of synthesis, intracellular assembly, and intraalveolar metabolism of this phospholipid-rich secretory product. Surfactant (approximately 90% lipid, 10% protein by weight) was purified by density gradient centrifugation of material obtained by lavaging rat lungs. The purified material was used to generate an antiserum from which a specific antibody was obtained by affinity chromatography. A horseradish peroxidase-labeled Fab was used to localize the antigen in rat lung. The antibody labeled the rough endoplasmic reticulum and Golgi apparatus of type II cells only. Some multivesicular bodies in type II cells were also labeled, but whether the antigen was present in lamellar bodies was uncertain. Phagosomes of alveolar macrophages were labeled as were similar inclusions in type I cells. Using indirect immunocytochemistry we determined that the labeling of alveolar cell surfaces does not represent the presence of a continuous layer of secreted surfactant. These results suggest that only the type II cell synthesizes surfactant protein and than mainly alveolar macrophages participate in its catabolism. The initial intracellular site of the association of protein with lipid may be multivesicular bodies as suggested previously by others.