Immunocytochemistry on Synthetic Pathways of Glycoproteins in Salivary Gland Acinar Cells.

在人或哺乳动物的唾液中，已经鉴定出50多种高分子量物质，如酶蛋白、免疫球蛋白和其他特异性蛋白。全唾液中的蛋白质主要来源于唾液腺分泌物，通过腺细胞的分泌颗粒分泌。另一方面，唾液腺细胞的分泌颗粒往往显示复杂的内部亚结构，但很少有人知道其内容物的分子组织或分泌蛋白的包装所涉及的机制。本研究应用免疫包埋后胶体金标记技术，对人和沙鼠唾液腺分泌蛋白进行标记，观察其在腮腺和颌下腺腺泡细胞高尔基体和分泌颗粒中的分布。与抗体的淀粉酶，富含脯氨酸的蛋白质和组胺，反应被发现在高尔基囊，未成熟和成熟的分泌颗粒，但标记与单克隆抗体的凝集素或多克隆抗体的过氧化物酶，被发现在反式高尔基囊，反式高尔基网络，未成熟和成熟的分泌颗粒，但不是在内侧和顺式高尔基囊。提示唾液腺腺泡细胞存在两种蛋白质合成途径。

In the human or mammalian saliva, more than 50 kinds of high molecular weight substances such as enzyme proteins, immunoglobulins and other specific proteins have been identified. The proteins in whole saliva are derived mainly from salivary glands secretion via the secretory granules of the gland cells. On the other hand, the secretory granules of salivary gland cells often display complex internal substructures, yet little is known of the molecular organization of their contents or the mechanisms involved in packaging of the secretory proteins. In the present study we used post-embedding immunogold labeling with antibodies to several secretory proteins of the human and mongolian gerbil salivary glands, to determine their distribution in the Golgi apparatus and secretory granules of the human and mongolian gerbil parotid and submandibular gland acinar cells. With antibodies to the amylase, proline-rich proteins and histatins, reactivity was found in the Golgi saccules, immature and mature secretory granules, but labeling with a monoclonal antibody to the agglutinin or a polyclonal antibody to the peroxidase, was found in the trans Golgi saccules, trans Golgi network, and immature and mature secretory granules, but not in the medial and cis Golgi saccules. These results suggest that there are two kinds of the protein synthetic pathway in the salivary gland acinar cells.