Abstract
Electron microscopic studies of metaplasia of epithelium in atrophic rhinitis and the normal human nasal epithelium was made.
In the present study the materials were obtained from the lower edge of the inferior nasal choncha. The materials were fixed in buffered osmium tetroxide, dehydrated, and embedded in Epon 812. Thin sections were stained with uranyl acetate followed by lead hydroxide.
The results obtained were follows:
The nasal epithelium consists of four kinds of cells; the ciliated cells, the goblet cells, the basal cells and the nonciliated cells found rarely. The fine structure of these cells is similar to that of the rat trachea reported by Rhodin and Dalhamn (1956).
In the case of atrophic rhinitis metaplastic epithelium is often found. Metaplastic epithelium is composed of three cell layers; the external layer, piling up of flat or oval cells with the long axis mainly parallel to the upper surface, the middle layer of spinous cells and the basal cell layer. Each cell is combined with irregularly tiny processes and desmosomes.
The intercellular space varies in width somewhat but is usually conspicuously dilated.
The tonofilaments are scattered over the whole cytoplasma. Most of them anastomose each other and some of them aggregate in larger bundles, mostly running parallel to the long axis of cells.
A lot of tiny processes, microvilli, are found on the upper surface of the metaplastic epithelium.
The basement membrane is observed close and parallel to the plasma membrane at the basal surface of the epithelial cells. It is about 0.15μ, approximately three times as thick as that of the normal nasal epithelium. The collagenous fibriles in the connective tissue layer adjacent to the basement membrane show considerable decrease in amount. Fibroblasts, leucocytes and other planocytes can often be found as infiltration in this layer.
