adrenergic receptor

(redirected from Adrenoreceptors)

adrenergic receptor

Etymology: L, ad + ren, kidney; Gk, ergon, work; L, recipere, to receive
a site in a sympathetic effector cell that reacts to adrenergic stimulation. Two types of adrenergic receptors are recognized: alpha-adrenergic, which act in response to sympathomimetic stimuli, and beta-adrenergic, which block sympathomimetic activity. In general, stimulation of alpha receptors is excitatory of the function of the host organ or tissue, and stimulation of the beta receptors is inhibitory.

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.

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

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.
References in periodicals archive ?
The severity of urinary symptoms appears to depend in part on smooth muscle tone in the prostate and bladder neck, which is mediated by alpha 1A adrenoreceptors," said Leonard S.
While previous research on BPH etiology tended to focus on testosterone and other hormones, more recent research suggests other factors may play a greater role in the development of BPH and LUTS - including inflammation, various growth factors, and adrenoreceptors.
Silodosin preferentially binds to the alpha (1A) receptors in the prostate, bladder neck, urethra, and vas deferens relative to cardiovascular associated adrenoreceptors, thereby maximizing target organ activity while minimizing the potential for blood pressure effects.
Blockade of these adrenoreceptors can cause smooth muscle in the bladder neck and prostate to relax, resulting in an improvement in urine flow and a reduction in symptoms of benign prostatic hyperplasia (BPH).
ARC-4558 targets peripheral a2 adrenoreceptors to relieve pain caused by damaged nerves in the skin.
Visceral fat cells are predominantly studded with structures known as beta adrenoreceptors, (10) which, when triggered by certain signals (prompted by reduced calorie intake, for example), stimulate the cells to undergo lipolysis.
The exact time-course of changes in expression of adrenoreceptors is not entirely clear, but probably occurs over four to 12 hours.
Presence of alpha-1 adrenoreceptors on thermosensitive neurons in the medial preoptico-anterior hypothalamic area in rats.
High circulating levels of epinephrine could create a neurocirculatory feedback loop that would promote syncope by stimulating [beta]-2 adrenoreceptors.
Noradrenaline acting on alpha-1 adrenoreceptors causes contraction of smooth muscle in these regions.
4-7) Both are trace endogenous bioamines, agonists of the [alpha]1, [alpha]2, [beta]1 and [beta]3 adrenoreceptors, are found in human plasma, platelets, sympathic nerves and adrenal tissue, and are present in Citrus aurantium (Seville orange, bitter orange), an ingredient in dietary supplements marketed for weight loss.