alpha-1 adrenergic receptor

• α1アドレナリン受容体、α1アドレナリンレセプター

関

adrenergic alpha-1 receptor、alpha-1 adrenoceptor、alpha1 adrenergic receptor、alpha1 adrenoceptor

WordNet

1. first in order of importance; "the alpha male in the group of chimpanzees"; "the alpha star in a constellation is the brightest or main star"
2. the 1st letter of the Greek alphabet
3. the beginning of a series or sequence; "the Alpha and Omega, the first and the last, the beginning and the end"--Revelations
4. early testing stage of a software or hardware product; "alpha version"
5. a cellular structure that is postulated to exist in order to mediate between a chemical agent that acts on nervous tissue and the physiological response
6. drug that has the effects of epinephrine (同)adrenergic_drug
7. relating to epinephrine (its release or action) (同)sympathomimetic
8. any high mountain

PrepTutorEJDIC

1. アルファ(ギリシア語アルファベットの第1字A,α;英語のA,aに相当) / アルファ星(星座の主星)
2. =sense organ / 受信装置
3. 高山,高峰

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2013/02/01 08:46:59」(JST)

wiki en

[Wiki en表示]

See also: Adrenergic receptor

The alpha-1 (α₁) adrenergic receptor is a G protein-coupled receptor (GPCR) associated with the G_q heterotrimeric G-protein. It consists of three highly homologous subtypes, including α_1A-, α_1B-, and α_1D-adrenergic. Catecholamines like norepinephrine (noradrenaline) and epinephrine (adrenaline) signal through the α₁-adrenergic receptor in the central and peripheral nervous systems.

Effects

The α₁-adrenergic receptor has several general functions in common with the α₂-adrenergic receptor, but also has specific effects of its own.

General

Common (or still unspecified) effects include:

• Vasoconstriction of arteries to heart (coronary arteries)
• Vasoconstriction of veins
• Decrease motility of smooth muscle in gastrointestinal tract

Specific

The primary effect is on smooth muscle, which it mainly constricts.^{[citation needed]} This may result in bronchospasm and anaphylaxis if stimulated by oxymetazoline or other alpha 1 agonists.

Stimulators

• Norepinephrine
• Epinephrine
• Other substances:
  • Metaraminol
• Phenylephrine

Smooth muscle

In smooth muscle of blood vessels the principal effect is vasoconstriction. Blood vessels with α₁-adrenergic receptors are present in the skin, the sphincters of gastrointestinal system, kidney (renal artery) and brain. During the fight-or-flight response vasoconstriction results in decreased blood flow to these organs. This accounts for the pale appearance of the skin of an individual when frightened.

It also induces contraction of the urinary bladder, although this effect is minor compared to the relaxing effect of β₃-adrenergic receptors. In other words, the overall effect of sympathetic stimuli on the bladder is relaxation, in order to delay micturition during stress. Other effects are on smooth muscle are contraction in:

• Ureter
• Hairs (arrector pili muscles)
• Uterus (when pregnant)
• Urethral sphincter
• Bronchioles (although minor to the relaxing effect of β₂ receptor on bronchioles)
• Iris dilator muscle
• Seminal tract, resulting in ejaculation

In a few areas the result on smooth muscle is relaxation. These include:

• The rest of the GI tract, except for the sphincters
• Blood vessels of erectile tissue

Neuronal

Activation of α₁-adrenergic receptors produces anorexia and partially mediates the efficacy of appetite suppressants like phenylpropanolamine and amphetamine in the treatment of obesity. Norepinephrine has been shown to decrease cellular excitability in all layers of the temporal cortex, including the primary auditory cortex. In particular, norepinephrine decreases glutamatergic excitatory postsynaptic potentials by the activation of α₁-adrenergic receptors.

Other

• Positive inotropic effect on heart muscle (α₁<<β₁) (in other words, strengthening the force of contraction)
• Secretion from salivary gland
• Increase salivary potassium levels
• Glycogenolysis and gluconeogenesis from adipose tissue and liver.
• Secretion from sweat glands
• Na⁺ reabsorption from kidney
  • Stimulate proximal tubule NHE3
  • Stimulate proximal tubule basolateral Na-K ATPase
• Activate mitogenic responses and regulate growth and proliferation of many cells
• Involved in the detection of mechanical feedback on the hypoglossal motor neurons which allow a long-term facilitation in respiration in response to repeated apneas.

Signaling cascade

α₁-Adrenergic receptors are members of the G protein-coupled receptor superfamily. Upon activation, a heterotrimeric G protein, G_q, activates phospholipase C (PLC), which causes an increase in IP₃ and calcium. This triggers further effects, primarily through the activation of an enzyme Protein Kinase C. This enzyme, as a kinase, functions by phosphorylation of other enzymes causing their activation, or by phosphorylation of certain channels leading to the increase or decrease of electrolyte transfer in or out of the cell.

Activity during exercise

During exercise these α₁-adrenergic receptors can be selectively blocked by sympathetic nervous activity, allowing the β₂-adrenergic receptors (which mediate vasodilation) to dominate. Note that only the α₁-adrenergic receptors in active muscle will be blocked. Resting muscle will not have its α₁-adrenergic receptors blocked, and hence the overall effect will be α₁-adrenergic-mediated vasoconstriction.^{[citation needed]}

Ligands

Agonists

• Butcher's Broom (Ruscus aculeatus)
• Cirazoline
• Etilefrine
• Metaraminol
• Methoxamine
• Midodrine
• Naphazoline
• Oxymetazoline
• Phenylephrine (decongestant)
• Synephrine
• Tetrahydrozoline
• Xylometazoline

Antagonists

• Alfuzosin (used in benign prostatic hyperplasia
• Arotinolol
• Carvedilol (used in congestive heart failure; it is a non-selective beta blocker)
• Doxazosin (used in hypertension and benign prostatic hyperplasia)
• Indoramin
• Labetalol (used in hypertension; it is a mixed alpha/beta adrenergic antagonist)
• Moxisylyte
• Phenoxybenzamine
• Phentolamine (used in hypertensive emergencies; it is a nonselective alpha-antagonist)
• Prazosin (used in hypertension)
• Silodosin
• Tamsulosin (used in benign prostatic hyperplasia)
• Terazosin
• Tolazoline
• Trimazosin

Various heterocyclic antidepressants and antipsychotics are α₁-adrenergic receptor antagonists as well. This action is generally undesirable in such agents and mediates side effects like orthostatic hypotension, and extrapyramidal symptoms

See also

• Adrenergic receptor

References

External links

• "Adrenoceptors". IUPHAR Database of Receptors and Ion Channels. International Union of Basic and Clinical Pharmacology. http://www.iuphar-db.org/GPCR/ChapterMenuForward?chapterID=1274.

UpToDate Contents

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English Journal

• Synthesis and structure-activity relationships of novel arylpiperazines as potent antagonists of α1-adrenoceptor.

• Silva RO1, de Oliveira AS1, Nunes Lemes LF2, de Camargo Nascente L2, Coelho do Nascimento Nogueira P3, Silveira ER3, Brand GD4, Vistoli G5, Cilia A6, Poggesi E6, Buccioni M7, Marucci G7, Bolognesi ML8, Romeiro LA9.
• European journal of medicinal chemistry.Eur J Med Chem.2016 Oct 21;122:601-10. doi: 10.1016/j.ejmech.2016.06.052. Epub 2016 Jun 30.
• Arylpiperazines 2-11 were synthesized, and their biological profiles at α1-adrenergic receptors (α1-ARs) assessed by binding assays in CHO cells expressing human cloned subtypes and by functional experiments in isolated rat vas deferens (α1A), spleen (α1B), and aorta (α1D). Modifications at the
• PMID 27448917

• Synthesis and activity of newly designed aroxyalkyl or aroxyethoxyethyl derivatives of piperazine on the cardiovascular and the central nervous systems.

• Waszkielewicz AM1, Monika K2, Katarzyna P3, Szczepan M2, Agata S4, Monika GL4, Anna G4, Barbara F2.
• Bioorganic & medicinal chemistry letters.Bioorg Med Chem Lett.2016 Sep 15. pii: S0960-894X(16)30977-5. doi: 10.1016/j.bmcl.2016.09.037. [Epub ahead of print]
• In the search for new hypotensive agents some new aroxyalkyl or aroxyethoxyethyl derivatives of piperazine have been synthesized and evaluated for their pharmacological properties. Pharmacological tests included receptor binding assays toward adrenergic receptors α1, α2 and β1, additionally 5-HT1
• PMID 27692547

• CgA1AR-1 acts as an alpha-1 adrenergic receptor in oyster Crassostrea gigas mediating both cellular and humoral immune response.

• Liu Z1, Zhou Z2, Wang L3, Qiu L2, Zhang H2, Wang H2, Song L4.
• Fish & shellfish immunology.Fish Shellfish Immunol.2016 Sep 12;58:50-58. doi: 10.1016/j.fsi.2016.09.022. [Epub ahead of print]
• We have now cloned an alpha-1 adrenergic receptor (A1AR) from the cDNA library of oyster Crassostrea gigas, designating as CgA1AR-1. The full length of CgA1AR-1 was 1149 bp and it encodes a protein of 382 amino acids containing a 7 transmembrane domain, whose putative topology was similar to the A1
• PMID 27633678

Japanese Journal

• 仙髄神経領域の帯状疱疹により排尿障害を合併した高齢患者の4例

• 松尾 朋博,大庭 康司郎,宮田 康好,井川 掌,酒井 英樹
• 泌尿器科紀要 = Acta urologica Japonica 60(2), 87-90, 2014-02
• … 9%1). … Moreover, the onset rate of herpes zoster with urinary dysfunction is 0.6%1). … All patients were elderly people (66-84 years old), and all patients were administered anti-virus drugs and alpha 1-adrenergic receptor blockers. …
• NAID 120005465995

• Reorganization of adult prefrontal cortex plasticity and function by neonatal hippocampus lesion-role of cortical alpha-1 adrenergic receptor signaling (第14回活性アミンに関するワークショップ)

• LK Srivastava,SK Bhardwaj,R Ryan [他]
• 分子精神医学 11(3), 219-221, 2011-07
• NAID 40018937163

• Four different ways of alternative transcripts generation mechanism in ADRA1A gene

• Huh Jae-Won,Kim Young-Hyun,Lee Sang-Rae [他],KIM Dae-Soo,PARK Sang-Je,KIM Hyoungwoo,KIM Ji-Su,SONG Bong-Seok,KIM Heui-Soo,CHANG Kyu-Tae
• Genes & genetic systems 85(1), 65-73, 2010-02-25
• … The ADRA1A (Alpha-1-adrenergic receptor) gene is one of the members of G protein-coupled receptor superfamily. … In this study, we conducted expression analysis and evolutionary characterization of alternative transcripts of the ADRA1A gene. …
• NAID 10029514568

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★リンクテーブル★

リンク元	「alpha-1 adrenoceptor」「adrenergic alpha-1 receptor」
関連記事	「adrenergics」「adrenergic」「alpha」「adrenergic receptor」

「alpha-1 adrenoceptor」

　　[★]

• α1アドレナリン受容体、α1アドレノセプター

関

alpha-1 adrenergic receptor、alpha1 adrenergic receptor、alpha1 adrenoceptor

「adrenergic alpha-1 receptor」

　　[★]

• アドレナリンα1受容体、アドレナリンα1レセプター

関

alpha-1 adrenergic receptor

「adrenergics」

　　[★]

アドレナリン受容体刺激薬、アドレナリン作用薬

関

adrenergic、adrenergic agent、adrenergic agonist、adrenergic drug、adrenergic receptor agonist

「adrenergic」

　　[★]

• adj.

• アドレナリンの、アドレナリン性の

　 　

「alpha」

　　[★]

α、アルファ

関

alfa

　 　 　 　 　

「adrenergic receptor」

　　[★] アドレナリン受容体