Alfa-2 adrenergički receptor

Alfa-2 (α₂) adrenergički receptor (ili adrenoceptor) je G protein-spregnuti receptor koji vezuje G_i heterotrimerni G protein. Postoje tri visoko homologna podtipa, α_2A-, α_2B-, i α_2C- adrenergički receptor. Neke vrste takođe izražavaju četvrti α_2D-adrenergički receptor.^[1] Kateholamini kao što su norepinefrin (noradrenalin) i epinefrin (adrenalin) prenose signal kroz α₂-adrenergički receptor u centralnom i perifernom nervnom sistemu.

Efekti

α₂-adrenergički receptor vezuje oba norepinefrin koga oslobađaju simpatička postgangliona vlakna i epinefrin (adrenalin) koga otpušta adrenalna medula. On vezuje epinefrin sa nešto većim afinitetom. On ima nekoliko opštih funkcija koje su zajedničke sa α₁-adrenergičkim receptorom, a takođe ima i niz specifičnih efekata.

Opšti

Opšti efekti su:

Vazodilatacija arterija^[2]
Vazokonstrikcija arterija ka srcu (koronarnih arterija)^[3], mada ekstent ovog efekta može da bude ograničen^[4]
Vazokonstrikcija vena^[5]
Umanjena motilnost glatkih mišića gastrointestinalnog trakta^[6]

Individualni

Individualna dejstva α₂ receptora su:

Posreduje sinaptičku transmisiju u pre- i postsinaptičkim nervnim terminalima
- Umanjuje otpuštanje acetilholina^[7]
- Umanjuje otpuštanje norepinefrina^[7]
  - Inhibira norepinefrinski sistem u mozgu
Inhibicija^[8] lipolize u adipoznom tkivu^[9]
Indukcija oslobađanja glukagona iz pankreasa
agregacija trombocita
Kontrakcija sfinktera gastrointestinalnog trakta
↓ Sekrecija iz pljuvačnih žlezdi^[10]

Ligandi

Agonisti

Antagonisti

Povezano

Adrenergički receptor

Reference

↑ Ruuskanen JO, Xhaard H, Marjamäki A, Salaneck E, Salminen T, Yan YL, Postlethwait JH, Johnson MS, Larhammar D, Scheinin M (January 2004). „Identification of duplicated fourth alpha2-adrenergic receptor subtype by cloning and mapping of five receptor genes in zebrafish”. Molecular Biology and Evolution 21 (1): 14–28. DOI:10.1093/molbev/msg224. PMID 12949138.
↑ Goodman Gilman, Alfred. Goodman & Gilman's The Pharmacological Basis of Therapeutics. Tenth Edition. McGraw-Hill (2001): Page 140.
↑ Woodman OL, Vatner SF (1987). „Coronary vasoconstriction mediated by α₁- and α₂-adrenoceptors in conscious dogs”. Am. J. Physiol. 253 (2 Pt 2): H388–93. PMID 2887122.
↑ Sun D, Huang A, Mital S, Kichuk MR, Marboe CC, Addonizio LJ, Michler RE, Koller A, Hintze TH, Kaley G (July 2002). „Norepinephrine elicits beta2-receptor-mediated dilation of isolated human coronary arterioles”. Circulation 106 (5): 550–5. PMID 12147535.
↑ Elliott J (1997). „Alpha-adrenoceptors in equine digital veins: evidence for the presence of both α₁ and α₂-receptors mediating vasoconstriction”. J. Vet. Pharmacol. Ther. 20 (4): 308–17. DOI:10.1046/j.1365-2885.1997.00078.x. PMID 9280371.
↑ Sagrada A, Fargeas MJ, Bueno L (1987). „Involvement of α₁ and α₂ adrenoceptors in the postlaparotomy intestinal motor disturbances in the rat”. Gut 28 (8): 955–9. DOI:10.1136/gut.28.8.955. PMC 1433140. PMID 2889649.
↑ ^7,0 ^7,1 Rang, H. P. (2003). Pharmacology. Edinburgh: Churchill Livingstone. str. 163. ISBN 0-443-07145-4.
↑ Wright EE, Simpson ER (1981). „Inhibition of the lipolytic action of beta-adrenergic agonists in human adipocytes by alpha-adrenergic agonists”. J. Lipid Res. 22 (8): 1265–70. PMID 6119348. Arhivirano iz originala na datum 2009-03-23. Pristupljeno 2014-03-27.
↑ Fitzpatrick, David; Purves, Dale; Augustine, George (2004). „Table 20:2”. Neuroscience (Third izd.). Sunderland, Mass: Sinauer. ISBN 0-87893-725-0.
↑ Khan ZP, Ferguson CN, Jones RM (1999). „alpha-2 and imidazoline receptor agonists. Their pharmacology and therapeutic role”. Anaesthesia 54 (2): 146–65. DOI:10.1046/j.1365-2044.1999.00659.x. PMID 10215710.
↑ ^11,0 ^11,1 Haenisch B, Walstab J, Herberhold S, Bootz F, Tschaikin M, Ramseger R, Bönisch H. (2010). „Alpha-adrenoceptor agonistic activity of oxymetazoline and xylometazoline”. Fundam Clin Pharmacol. 24 (6): 729-39. PMID 20030735.

Literatura

Fitzpatrick, David; Purves, Dale; Augustine, George (2004). „Table 20:2”. Neuroscience (Third izd.). Sunderland, Mass: Sinauer. ISBN 0-87893-725-0.
Rang, H. P. (2003). Pharmacology. Edinburgh: Churchill Livingstone. str. 163. ISBN 0-443-07145-4.

Spoljašnje veze

„Adrenoceptors”. IUPHAR Database of Receptors and Ion Channels. International Union of Basic and Clinical Pharmacology. Arhivirano iz originala na datum 2015-01-12.

[pmid12949138-1] Ruuskanen JO, Xhaard H, Marjamäki A, Salaneck E, Salminen T, Yan YL, Postlethwait JH, Johnson MS, Larhammar D, Scheinin M (January 2004). „Identification of duplicated fourth alpha2-adrenergic receptor subtype by cloning and mapping of five receptor genes in zebrafish”. Molecular Biology and Evolution 21 (1): 14–28. DOI:10.1093/molbev/msg224. PMID 12949138.

[2] Goodman Gilman, Alfred. Goodman & Gilman's The Pharmacological Basis of Therapeutics. Tenth Edition. McGraw-Hill (2001): Page 140.

[pmid2887122-3] Woodman OL, Vatner SF (1987). „Coronary vasoconstriction mediated by α₁- and α₂-adrenoceptors in conscious dogs”. Am. J. Physiol. 253 (2 Pt 2): H388–93. PMID 2887122.

[pmid12147535-4] Sun D, Huang A, Mital S, Kichuk MR, Marboe CC, Addonizio LJ, Michler RE, Koller A, Hintze TH, Kaley G (July 2002). „Norepinephrine elicits beta2-receptor-mediated dilation of isolated human coronary arterioles”. Circulation 106 (5): 550–5. PMID 12147535.

[pmid9280371-5] Elliott J (1997). „Alpha-adrenoceptors in equine digital veins: evidence for the presence of both α₁ and α₂-receptors mediating vasoconstriction”. J. Vet. Pharmacol. Ther. 20 (4): 308–17. DOI:10.1046/j.1365-2885.1997.00078.x. PMID 9280371.

[pmid2889649-6] Sagrada A, Fargeas MJ, Bueno L (1987). „Involvement of α₁ and α₂ adrenoceptors in the postlaparotomy intestinal motor disturbances in the rat”. Gut 28 (8): 955–9. DOI:10.1136/gut.28.8.955. PMC 1433140. PMID 2889649.

[Rang163-7] 7,0 ^7,1 Rang, H. P. (2003). Pharmacology. Edinburgh: Churchill Livingstone. str. 163. ISBN 0-443-07145-4.

[pmid6119348-8] Wright EE, Simpson ER (1981). „Inhibition of the lipolytic action of beta-adrenergic agonists in human adipocytes by alpha-adrenergic agonists”. J. Lipid Res. 22 (8): 1265–70. PMID 6119348. Arhivirano iz originala na datum 2009-03-23. Pristupljeno 2014-03-27.

[purves-9] Fitzpatrick, David; Purves, Dale; Augustine, George (2004). „Table 20:2”. Neuroscience (Third izd.). Sunderland, Mass: Sinauer. ISBN 0-87893-725-0.

[pmid10215710-10] Khan ZP, Ferguson CN, Jones RM (1999). „alpha-2 and imidazoline receptor agonists. Their pharmacology and therapeutic role”. Anaesthesia 54 (2): 146–65. DOI:10.1046/j.1365-2044.1999.00659.x. PMID 10215710.

[xyloOxy-11] 11,0 ^11,1 Haenisch B, Walstab J, Herberhold S, Bootz F, Tschaikin M, Ramseger R, Bönisch H. (2010). „Alpha-adrenoceptor agonistic activity of oxymetazoline and xylometazoline”. Fundam Clin Pharmacol. 24 (6): 729-39. PMID 20030735.

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