HISTOCHEMICAL DEMONSTRATION OF NORADRENALINE IN RAT SALIVARY GLANDS

Abstract

The localization of tissue noradrenaline [norepinephrine] in rat salivary glands has been studied by a fluorescence method for histochemical demonstration of catecholamines in combination with a pharmacological approach. In the submaxillary gland, norepinephrine fluorescence showed a fine network surrounding the secretory acini and the granular tubules, but there was no fluorescence in their cell bodies. The walls of arteries and arterioles were also surrounded by norepinephrine fluorescence but the intra- and interlobular excretory ducts were not. In the sublingual gland, norepinephrine fluorescence was present only in the walls of blood vessels and there was no fluorescence in the vicinity of the secretory acini and the excretory ducts. The localization of noradrenalide in the parotid gland was essentially similar to that of the submaxillary gland but somewhat weaker in intensity around the secretory acini. This indicates that the adrenergic innervation is predominant to the submaxillary and, to a lessor extent, parotid glands which are composed of serous cells and that there is no supply of adrenergic fibers to the mucous cells of the sublingual gland. The results of quantitative determination of norepinephrine with a biochemical method were well consistent with those of histochemical findings. In connection with the distribution of specific cholinesterase, the mode of double innervation of adrenergic and cholinergic fibers to the salivary glands are discussed.