Electrically-evoked catecholamine release from cat adrenals. Role of cholinergic receptors

Détails

ID Serval
serval:BIB_404489E9A41F
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
Electrically-evoked catecholamine release from cat adrenals. Role of cholinergic receptors
Périodique
Biochem Pharmacol
Auteur(s)
Alamo  L., Garcia  A. G., Borges  R.
ISSN
0006-2952
Statut éditorial
Publié
Date de publication
08/1991
Peer-reviewed
Oui
Volume
42
Numéro
5
Pages
973-8
Notes
Journal Article
Research Support, Non-U.S. Gov't --- Old month value: Aug 8
Résumé
Catecholamine (CA) release from perfused cat adrenal glands was continuously monitored using an on-line system coupled to an electrochemical detector. This highly sensitive procedure allowed the detection of small changes in the rate of secretion, even using short trains of electrical stimulation or brief acetylcholine (ACh) pulses. CA release was linear with increasing strength of ACh, transmural or splanchnic nerve stimulation. By using specific blockers, the contribution of nicotinic or muscarinic receptors to the overall secretory response to various stimuli could be established. That nicotinic receptors play a major role in mediating the secretory response to all stimuli is shown by the clear inhibition of the response with mecamylamine (10 microM). In contrast, atropine (1 microM) halved secretion evoked by ACh or nerve stimulation but had little effect on the response to trains of transmural electrical stimulation. When transmural electrical stimulation was applied continuously (instead of in trains), increasing the frequency in a step-wise manner, a bell-shaped curve was obtained; secretion reached a peak at 8 Hz and then declined sharply at 16 and 32 Hz. With this stimulation pattern, atropine decreased by 50% the secretion response at the higher frequencies (4-32 Hz). Very few studies are available which define the role of receptors and ionic channels in mediating electrically-evoked CA release. These stimulation patterns have not been used previously and are likely to mimic more closely than those used in earlier studies the physiologic firing pattern of splanchnic nerves innervating adrenomedullary cells.
Mots-clé
Acetylcholine/pharmacology Adrenal Glands/innervation/*secretion Animals Atropine/pharmacology Catecholamines/*metabolism Cats Electric Stimulation Female Male Mecamylamine/pharmacology Receptors, Muscarinic/drug effects/*physiology Receptors, Nicotinic/drug effects/*physiology Splanchnic Nerves/physiology
Pubmed
Web of science
Création de la notice
08/04/2008 15:47
Dernière modification de la notice
20/08/2019 13:38
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