Light and scanning electron microscopic investigation of the laryngeal mucosa of Syrian golden hamsters

Abstract

The laryngeal epithelium of Syrian golden hamsters (SGH) at 8, 12.5 and 17 months was studied by scanning electron microscopy (SEM) and light microscopy (LM). Stratified squamous epithelium, covered with shallow microvilli or microplicae, was observed covering the upper two-thirds of the laryngeal epiglottis, the false folds, the vocal cords and the luminal protrusions of the arytenoid cartilages. Pseudostratified respiratory epithelium, characterized by mucus producing cells with microvilli and ciliated cells, covered the base of the epiglottis and the entire subglottis. Transitional zones between squamous and respiratory epithelium were composed of stratified cuboidal epithelium. Towards the base of the epiglottis cuboidal cells with a relatively large surface area were present which displayed short surface microvilli, while cells with a small surface area were covered with long microvilli. Age related changes were not observed. Degenerative changes of submucosal glands or cartilages occurred in almost every animal, but no epithelial lesions were found. The findings confirm a low incidence of spontaneous metaplasia in the laryngeal epithelium of the SGH.