Parasympathetic-mediated reflex salivation and vasodilatation in the cat submandibular gland

Abstract

The aim of the present study was to compare and characterize the secretory and vasodilator effects induced by chorda lingual nerve (CLN) stimulation (i.e., direct parasympathetic stimulation) and reflex parasympathetic stimulation in the submandibular gland (SMG) of sympathectomized cats. The increase in blood flow and salivary secretion in response to electrical stimulation of the central cut ends of the vagus and inferior alveolar nerves, as well as to stimulation of the CLN at a site approximately 5 mm distal to the intersection of the CLN and the SMG duct (site D) was completely abolished by section of the chorda tympani nerve (CTN). Neither response to CLN stimulation at a site nearly 5 mm proximal to the intersection of the CLN and the SMG duct (site C) was affected by CTN section. Section of the CLN at a site approximately 5 mm distal to the intersection of the CTN and the CLN abolished the submandibular salivary and vasodilator responses elicited by CLN stimulation at site D but had no effect on the two responses evoked by CLN stimulation at site C. The blood flow increases evoked by electrical stimulation of the CLN at site D were greatly reduced by prior treatment with the autonomic ganglion blocker hexamethonium, but the vasodilator responses evoked from site C were reduced much less. These data suggest that the secretory and vasodilator responses elicited by CLN stimulation at site D and those by vagus and inferior alveolar nerve stimulation are mediated largely via a parasympathetic reflex mechanism.(ABSTRACT TRUNCATED AT 250 WORDS)

Roles of lysosomal proteolytic systems in AQP5 degradation in the submandibular gland of rats following chorda tympani parasympathetic denervation

“…Parasympathetic stimulation is known to provoke salivary secretion strongly (21). Besides the role of parasympathetic nerves in saliva secretion, AQP5 is also known to play a major role in saliva secretion (35,43).…”

“…The SMG was dissected on days 1,4,7,10,14,21, and 28 after bilateral CTD and weights were measured. Rats with no operation (0 day) were regarded as the control in the present study.…”

In vitro and in vivo imaging of intracellular Ca2+ responses in salivary gland cells

“…These results suggest that secretion occurs subsequent to a delay period following the increase in [Ca 2 þ ] i . The involvement of blood flow in salivary secretion was suggested by the induction of salivation and the increase of blood flow in the SMG due to parasympathetic stimulation [49,50]. Monitoring blood flow in the SMG together with Ca 2 þ responses using a laser speckle imaging flowmeter demonstrated that mAChR stimulation-induced changes in blood flow were synchronized with the increase in [Ca 2 þ ] i and salivary secretion in the SMG.…”

“…The Izumi group has reported that parasympathetic stimulation induces salivary secretion and increased blood flow [49,50]. In addition, taste stimuli such as sour, bitter, sweet, salty, and umami, also induce salivary secretion [51].…”

Suppression of carbachol-induced oscillatory Cl−secretion by forskolin in rat parotid and submandibular acinar cells

“…Agonist-induced fluid secretion from salivary glands in vivo is potentiated by cAMP-increasing agents (6,22,25), though the fluid secretion is reduced by the agents when doses of a muscarinic agonist and/or a cAMP-increasing agent are high (6). In addition, intravenous injection of cAMP-increasing agents induce a transient increase in glandular blood flow (25), whereas the vascular modulation around the salivary glands by parasympathetic nerve is postulated to be involved in the mechanism of the prominent salivation in vivo (15,24). Taken together, fluid secretion from salivary glands may basically depend on Cl Ϫ secretion, and other factors such as the increase in glandular blood flow also may affect the fluid secretion in in vivo experiments, especially at low doses.…”