The Mode of Action of Reserpine on the Salivary Secretion of the Submaxillary Gland in Dog

Abstract

Shimamoto and his coworkers (1-3) of this laboratory have shown that the adre nergic innervation of the submaxillary gland in dog mainly inhibits the cholinergically salivary secretion, especially in winter.In the dog anesthetized with amobarbital sodium they showed 1) that stimulation of the cervical sympathetic nerve or the splanchnic nerve depressed or blocked the salivary responses to stimulation of the chorda tympani and to administration of pilocarpine or acetylcholine, 2) that the intravenous injection of adrenaline or noradrenaline blocked the same responses as well, 3) that though the injection of relatively large doses of the amine elicited slight and transient secretion of the saliva with the characteristic property, the repetition of the injection progressively decreased the secretion and at last abolished it, and 4) that the inhibitory effects of the amines or the same effects obtained by stimulation of the splanchnic nerve on the cholinergically induced salivary secretion were more marked in the sympathetically denervated gland than the normal one. Further it is worth to mention that the inhibitory effects of the amines on the salivary secretion were long lasting and much stronger in winter than in summer.It has been already reported that the submaxillary gland of various animals contains appreciable amount of catecholamine, in which noradrenaline is dominant (4, 5). Bog danski et al. (6) showed that the salivary response of the submaxillary gland in dog to tetrabenazine was maximal three hours after the injection and it was blocked by administration of atropine and chlorisodamine and also by severance of the chorda tympani. They concluded that the salivary response to tetrabenazine derived from the central parasympathetic stimulation produced by the drug.Supposedly, the study of the deprivation of catecholamine in the submaxillary gland may give some clue to know the mode of action of the sympathetic innervation on the salivary secretion. In this report the effects of reserpine on the salivary responses of the gland were analyzed in the dog anesthetized with amobarbital sodium and also in the spinal dog. METHODSMongrel dogs of 5 to 15 kg of body weight were used. The animals were anesthe

Depletion of Catecholamine by Reserpine in the Innervated and Denervated Submaxillary Glands of Rats

“…The submaxillary gland contains a relatively large amount of noradrenaline (4). Yamawaki (5) has shown that the profuse, spontane ous flow of the submaxillary saliva begins to manifest in association with sedation caused by reserpine in an unanesthetized dog, and is abolished by sectioning of the chorda tympani. However, the spontaneous flow of saliva turns to a decrease at the time when the endogenous catecholamines in the brain, heart and adrenal glands are maximally depleted (6).…”