Ultrastructural and fluorescence histochemical studies on the sympathetic innervation of the canine laryngeal glands.

The existence of the adrenergic terminals of the canine laryngeal glands has been revealed by electron microscopy and fluorescence histochemistry. Adrenergic fibres with fluorescent varicosities were observed around the base of th acini in the submucosa. In dogs treated with 5-OHDA, varicosities containing both small and large, dense-cored vesicles containing both small and large, dense-cored vesicles, believed to be adrenergic terminals, were found near blood vessels, gland cells and myoepithelial cells in the submucosal gland region. The role of these adrenergic terminals is briefly discussed.