adrenergic receptor

(redirected from Beta-adrenoceptors)

Adrenergic Receptor

Any of a family of G protein-coupled cell membrane receptors which receive neuronal impulses from postganglionic adrenergic fibres of the sympathetic nervous system, which are divided into:
(1) Alpha receptors, which evoke an excitatory response of smooth muscle cells to catecholamines. Alpha receptors are divided into alpha1 (Gq) and alpha2 (Gi) coupled receptors.
Selective agonist, alpha receptor Phenylephrine
Alpha receptor effects Vasoconstriction, reduced GI tract motility.
(2) Beta receptors, which dampen the response to catecholamines. Beta receptors are divided into beta1, beta2, beta3, which are linked to Gs, and adenylate cyclase, increasing cAMP, which in turn drives cAMP-dependent protein kinase that mediates intracellular events.
Selective agonist, beta receptor Isoprenaline
Beta receptor effects Increased cardiac output, increased renin secretion from juxtaglomerular cells, increased gastric ghrelin secretion, smooth muscle relaxation resulting in bronchodilation, reduced GI motility, relaxation of detrusor muscle of the bladder, lipolysis, glycogenolysis and gluconeogenesis, increased renin secretion, insulin secretion, vasodilation, anabolism and thermogenesis of skeletal muscle.
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.

adrenergic receptor

Neurophysiology Any of a family of cell membrane receptors that receive neuronal impulses from postganglionic adrenergic fibers from the sympathetic nervous sytem, which are divided into α receptors, which results in an excitatory response of smooth muscle cells to catecholamines, and β receptors, which result in an inhibitory response to catecholamines; the GI tract is an exception, in that either α or β receptor stimulation results in relaxation
McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.

Adrenergic receptor

There are three families of adrenergic receptors, alpha1, alpha2 and beta, and each family contains three distinct subtypes. Each of the nine subtypes are coded by separate genes, and display specific drug specificities and regulatory properties.
Gale Encyclopedia of Medicine. Copyright 2008 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
Role of beta-adrenoceptors in memory consolidation: beta3-adrenoceptors act on glucose uptake and beta2-adrenoceptors on glycogenolysis.
Imaging of beta-adrenoceptors in the human thorax using (s)-[11C]CGP12388 and positron emission tomography.
Limas, "Autoantibodies against beta-adrenoceptors in human idiopathic dilated cardiomyopathy," Circulation Research, vol.
Kuroda, "Clozapine- and olanzapine-induced Fos expression in the rat medial prefrontal cortex is mediated by beta-adrenoceptors," Neuropsychopharmacology, vol.
Patel, "Exercise training initiated after the onset of diabetes preserves myocardial function: effects on expression of beta-adrenoceptors," Journal of Applied Physiology, vol.
The number of beta-adrenoceptors has been shown to decrease in salivary glands of rats treated with beta-adrenergic agent and demonstrates that the down-regulation of beta-adrenoceptors in the tissue can occur [22].
(30) These findings supported the premise that stimulation of beta-adrenoceptors with adrenoceptor agonists before an elective CS may promote postnatal respiratory and metabolic adaptation.
Ephedrine also has an effect on beta-adrenoceptors. Alpha-adrenergic vasoconstrictors diminish nasal obstruction, but they have no influence on itching, sneezing, and nasal secretion.
Different atypical beta-adrenoceptors mediate isoprenaline-induced relaxation in vascular and non-vascular smooth muscles.

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