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

在人类或哺乳动物的唾液中，已鉴定出50多种高分子量物质，如酶蛋白、免疫球蛋白等特定蛋白。全唾液中的蛋白质主要来自唾液腺分泌，通过腺体细胞的分泌颗粒。另一方面，唾液腺细胞的分泌颗粒通常具有复杂的内部亚结构，但对其内容物的分子组织或涉及分泌蛋白包装的机制知之甚少。在本研究中，我们用包埋后免疫金标记人和蒙古沙鼠唾液腺的几种分泌蛋白，以确定它们在人和蒙古沙土鼠腮腺和颌下腺腺泡细胞的高尔基体和分泌颗粒中的分布。在高尔基体球囊、未成熟和成熟的分泌颗粒中可见阳性反应，但在反式高尔基体球囊、反式高尔基体网、未成熟和成熟的分泌颗粒中未见反应。这些结果表明，涎腺腺泡细胞中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.