MORPHOLOGICAL AND HISTOCHEMICAL-STUDY OF HUMAN SUBMUCOSAL LARYNGEAL GLANDS

Background: The respiratory submucosal glands are a major source of se cretions in the airway. Human submucosal laryngeal glands have been sc arcely studied, with no works existing about their ultrastructure and histochemistry. Methods: Samples of epiglottis, ventricle, false vocal folds and true vocal folds were fixed in 10% buffered formalin for hi stochemical study with conventional and carbohydrate lectin histochemi stry, Other samples were fixed in 2.5% glutaraldehyde and conventional ly processed for transmission electron microscopy. Results: The human submucosal laryngeal glands are composed of serous tubules; mucous tub ules; collector duct; and final portion of this duct. The serous cells showed sialosulphomucins and affinity for WC;A and Con-A lectins. Wit h a previous treatment with neuraminidase, they also labelled with PNA . The mucous cells contained sialosulphomucins and showed affinity for WGA and DBA lectins in the samples proceeding from blood group A, and for WGA, VEA-I and LTA with those from blood group O. Ultrastructural ly, the serous cells presented a wide variety of granules, cells in wh ich seromucous granules predominated. The mucous cells presented large r-sized granules which were very electron-lucent. The collector duct w as composed of mitochondria-rich cells and basal cells. A cell which w e have termed ''intermediate'' was identified in the transition zone b etween the mucous tubules and the collector duct, and in the final por tion of the collector duct. It had morphological characteristics as if it were a transition between a goblet cell and collector duct cell. S ome nerve endings with cholinergic and peptidergic vesicles were found among the myoepithelial cells.Conclusions: These glands presented som e histological differences from the bronchial glands, the mucous secre tion was related to the blood group antigens, and the serous cells sho wed a wide variability in their secretory granules, many of them being of a seromucous type. (C) 1994 Wiley-Liss, Inc.