Non-cholinergic, vagally evoked gastric relaxation in the rat
Non-cholinergic, vagally evoked gastric relaxation in the rat
The vagus nerve exerts both excitatory and inhibitory influences over gastric smooth muscle tone. Excitatory influences are mediated by cholinergic preganglionic parasympathetic neurones which activate intramural ganglion cells through nicotinic ganglionic transmission. These latter neurones release acetylcholine which then acts at muscarinic receptors on gastric smooth muscle itself, causing it to contract.
Most investigations of vagally mediated gastric smooth muscle relaxation have concentrated on pathways resistant to muscarinic antagonists. These inhibitory pathways have generally been ascribed to the release of non-adrenergic, non-cholinergic inhibitory transmitters from intrinsic intramural neurones.
There is some, largely morphological, evidence that preganglionic parasympathetic vagal fibres may use other transmitters in addition to acetylcholine. Candidates include catecholamines, L-3,4-dihydroxyphenylalanine, 5-hydroxytryptamine and a variety of neuropeptides. This study represents an attempt to identify a role for such transmitters in vagally mediated gastric relaxation following nicotinic ganglion blockade.
The data in the present study suggest that there is an inhibitory non-cholinergic preganglionic parasympathetic vagal pathway to gastric smooth muscle which is resistant to both nicotinic and muscarinic receptor blockade. This non-cholinergic pathway appears to involve a catecholaminergic component and a nitroxergic component. The role of histamine, 5-hydroxytryptamine, prostaglandins, endogenous opioids and L-3,4-dihydroxyphenylalanine in this pathway is also examined. Such a non-cholinergic vagal influence is likely to play an important role in physiological phenomena such as the relaxation of the stomach that occurs in response to a meal or emetic stimuli.
University of Southampton
1994
Carnell, Anthony James
(1994)
Non-cholinergic, vagally evoked gastric relaxation in the rat.
University of Southampton, Doctoral Thesis.
Record type:
Thesis
(Doctoral)
Abstract
The vagus nerve exerts both excitatory and inhibitory influences over gastric smooth muscle tone. Excitatory influences are mediated by cholinergic preganglionic parasympathetic neurones which activate intramural ganglion cells through nicotinic ganglionic transmission. These latter neurones release acetylcholine which then acts at muscarinic receptors on gastric smooth muscle itself, causing it to contract.
Most investigations of vagally mediated gastric smooth muscle relaxation have concentrated on pathways resistant to muscarinic antagonists. These inhibitory pathways have generally been ascribed to the release of non-adrenergic, non-cholinergic inhibitory transmitters from intrinsic intramural neurones.
There is some, largely morphological, evidence that preganglionic parasympathetic vagal fibres may use other transmitters in addition to acetylcholine. Candidates include catecholamines, L-3,4-dihydroxyphenylalanine, 5-hydroxytryptamine and a variety of neuropeptides. This study represents an attempt to identify a role for such transmitters in vagally mediated gastric relaxation following nicotinic ganglion blockade.
The data in the present study suggest that there is an inhibitory non-cholinergic preganglionic parasympathetic vagal pathway to gastric smooth muscle which is resistant to both nicotinic and muscarinic receptor blockade. This non-cholinergic pathway appears to involve a catecholaminergic component and a nitroxergic component. The role of histamine, 5-hydroxytryptamine, prostaglandins, endogenous opioids and L-3,4-dihydroxyphenylalanine in this pathway is also examined. Such a non-cholinergic vagal influence is likely to play an important role in physiological phenomena such as the relaxation of the stomach that occurs in response to a meal or emetic stimuli.
This record has no associated files available for download.
More information
Published date: 1994
Identifiers
Local EPrints ID: 462827
URI: http://eprints.soton.ac.uk/id/eprint/462827
PURE UUID: 6cafe2ec-7730-40f4-9fbf-26230c7bb514
Catalogue record
Date deposited: 04 Jul 2022 20:12
Last modified: 04 Jul 2022 20:12
Export record
Contributors
Author:
Anthony James Carnell
Download statistics
Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.
View more statistics