Ultrastructural Study on Experimental Lingual Carcinogenesis in the Hamster. I. Ultrastructural Study of Normal Tongue Epithelium with Special Reference to the Process of Keratinization

The main purpose of the present series of studies is to investigate disorders of keratinization in experimental chemical lingual carcinogenesis in hamster. To our knowledge, no detailed ultrastructural study of the tongue epithelium in normal hamster is available. Thus as preliminary work attention was focused on the detailed description of the ultrastructure of the epithelium from the lateral surface of normal hamster tongue with special reference to the process of keratinization. The lateral epithelium in normal hamster tongue was composed of the epithelial parts which constituted the fili form papillae and the interpapillary epithelial part which occupied a greater portion of the lateral epithelium. The former was separated into the epithelial parts of the anterior and posterior sides of the papillae. The ultrastructural findings, especially keratohyalin granules showed considerable changes among these epithelial parts as well as under some fixation methods. These findings observed in the tongue lateral epithelium in hamster were weighed against ultrastructures in other keratinizing epithelia excepting the tongue epithelium