CYTOLOGICAL LOCALIZATION OF NORADRENALINE, MONOAMINE OXIDASE AND ACETYLCHOLINESTERASE IN SALIVARY GLANDS OF DOG

Abstract

The cytological localization of noradrenaline, monoamine oxidase and acetylcholinesterase was examined in the salivary glands of the dog. The noradrenaline-fluorescent nerve fibers surrounded the secretory acini of the submaxillary, sublingual and parotid glands, but the density in the sublingual gland was much less than in the other two glands. Noradrenaline fluorescence was not seen in the cytoplasms of the acinar cells nor in the vicinity of the excretory ducts. Intense fluorescence was present outside the smooth muscle layer in various sized arteries. The distribution of monoamine oxidase activity was different from that of noradrenaline fluoresence. All the cells of the secretory acini and the excretory ducts were evenly stained. The distribution of fibers showing acetylcholinesterase activity was different from that of noradrenaline-fluorescent fibers only in that the former fibers were present around the excretory ducts as well. The composition of secretory cells in the submaxillary and sublingual glands is different in dogs and rats. However, the cytological localization of noradrenaline, monoamine oxidase and acetylcholinesterase activities in the salivary glands of the dog was essentially similar to those of the rat. It was concluded, therefore, that the autonomic nerve supply to the salivary glands does not correlate with the type of secretory cells.