alpha receptor


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Related to alpha receptor: beta receptor

alpha receptor

any of the postulated adrenergic components of receptor tissues that respond to norepinephrine and to various blocking agents. The activation of alpha receptors causes physiologic responses such as increased peripheral vascular resistance, pupil dilation, and contraction of arrector muscles. Also called alpha-adrenergic receptor. Compare beta receptor.

alpha receptor

A pair of G protein-coupled cell membrane receptors in the sympathetic nervous system, which evoke an excitatory response of smooth muscle cells to catecholamines.
Alpha1 (Gq) coupled receptors cause smooth muscle contraction, resulting in vasoconstriction in the skin, GI tract, kidney and brain, as well as causing smooth muscle contraction in the ureter, vas deferens, arrector pili (hair–“goosebumps”), pregnant uterus, and elsewhere. Alpha1 receptor activation is also linked to  glycogenolysis and gluconeogenesis in fat and liver, sweating, and sodium absorption in the kidneys.
Alpha2 (Gi) coupled receptors inhibit insulin secretion, trigger glucagon release (pancreas), contract GI sphincters, inhibit presynaptic release of noradrenaline in the CNS, and increase platelet aggregation.
References in periodicals archive ?
If the mice missing the alpha receptor still had a functional beta version, their bodies still could respond to estrogen.
The firm also markets DIBENZYLINE(R), a non-selective alpha receptor blocker approved for the control of the hypertensive crises associated with pheochromocytoma, a tumor of the adrenal gland.
There are a number of physiological events which contribute to the erectile response, from alpha receptor antagonist's promotion of arterial flow to the synergistic effects of NO and PDE inhibitors on increasing smooth muscle relaxation," said Dr.
These nine articles describe some of the work being done to differentiate markers and use their presence to detect and treat a range of cancers, addressing the characterization of breast cancer subtypes in a large retrospective study, intraocular lymphoma markers, polymorphisms in genes associated with certain T-cell lymphomas, tumor antigens that are markers of minimal residual disease in acute myeloid leukemia, thyroid tumor markers, activity and expression of dipeptidyl peptidase IV and cathepsin H in human cutaneous melanoma compared to other common cancers, melanoma inhibitory activity as a serological marker in metastic melanoma, and the promise (or myth) of the tumor necrosis factor alpha receptors p55 and p75 in ovarian cancer detection.
Alpha receptors cause body fat to be stored in our system, while beta receptors cause it to be released.