Localization Of Secretory Component Research Articles

Immunoelectron microscopic study on the histogenesis of epidermoid metaplasia in respiratory epithelium.

To elucidate the histogenesis of epidermoid metaplasia with an immunoelectron microscopic method, we studied the localization of secretory component (SC), a differentiation marker of the epithelial cell, in human bronchial epithelium. In the area of normal epithelium, SC was synthesized by mucous cells, particularly by small mucous granule cells. It was also found with small mucous granules in both superficial columnar or cuboidal cells in the area of stratification and superficial, less flattened cells in the area of epidermoid metaplasia, but SC was not identified in polygonal cells under the superficial SC-positive cells in both of the above areas. These superficial cells containing SC and small mucous granules possessed increasing number of tonofilaments parallel with the degree of flattening of the surface cells. On the other hand, in the advanced epidermoid metaplasia, in which surface cells were composed of very flattened cells, SC and small mucous granules were not found in the bronchial epithelium. Tonofilaments increased in number in the cytoplasm parallel to morphologic changes from basal cells to outermost flattened cells, via polygonal cells. These findings suggest that small mucous granule cells containing SC could gradually change to flattened cells through a quantitative change of a cytoplasmic component, such as SC or tonofilaments, and constitute the superficial cells of initial epidermoid metaplasia, in which surface cells are composed of less flattened cells. Moreover, these findings suggested that basal cells play an important role in epidermoid differentiation.

Localization of free secretory component in pleomorphic adenomas of minor salivary gland origin.

Secretory component (a glycoprotein) is an antigenically distinct portion of the secretory immunoglobulin A, which has been identified in a number of normal and neoplastic epithelial cells. Localization of secretory component was determined in pleomorphic adenomas of minor salivary gland origin using the four-step peroxidase-antiperoxidase technique. Antiserum that detected only free secretory component (FSC) was used. Staining for secretory component was noted in the epithelium that lined duct-like spaces; but was absent in myoepithelial cells and mucous acini. These findings suggest a role for FSC in evaluating the histogenesis of various salivary gland neoplasms.

Ultrastructural localization of secretory component and carcinoembryonic antigen in human gastric neoplasms and related disorders

Ultrastructural localization of secretory component and carcinoembryonic antigen in human gastric neoplasms and related disorders

Secretory component and IgA in endometrial adenocarcinomas. An immunohistochemical study.

The localization of secretory component (SC) and IgA was immunohistochemically studied in 6 normal endometrium and 55 endometrial adenocarcinomas including 34 well, 11 moderately and 10 poorly differentiated ones. In normal endometrium, SC localization was found in the cytoplasm of epithelial cells and luminal contents of the gland. IgA showed similar localization of SC. Secretory phase endometrium contained proportionally larger numbers of positive cells for SC and IgA than proliferative phase endometrium. SC localization was found in all cases of well and moderately differentiated carcinomas, while it was found only in 4 cases out of 10 poorly differentiated carcinomas. IgA localization was similar to that of SC and this condition was thought to reveal the binding of IgA to SC existing in the tumor cells. The present immunohistochemical study revealed that the staining intensity of SC well correlated with the histological grade of differentiation of the tumors.