Adrenergic receptor
The adrenergic receptors or adrenoceptors are a class of G protein-coupled receptors that are targets of many catecholamines like norepinephrine (noradrenaline) and epinephrine (adrenaline) produced by the body, but also many medications like beta blockers, beta-2 (
Many cells have these receptors, and the binding of a catecholamine to the receptor will generally stimulate the sympathetic nervous system (SNS). The SNS is responsible for the fight-or-flight response, which is triggered by experiences such as exercise or fear-causing situations. This response dilates pupils, increases heart rate, mobilizes energy, and diverts blood flow from non-essential organs to skeletal muscle. These effects together tend to increase physical performance momentarily.
History
[edit]By the turn of the 19th century, it was agreed that the stimulation of sympathetic nerves could cause different effects on body tissues, depending on the conditions of stimulation (such as the presence or absence of some toxin). Over the first half of the 20th century, two main proposals were made to explain this phenomenon:
- There were (at least) two different types of neurotransmitters released from sympathetic nerve terminals, or
- There were (at least) two different types of detector mechanisms for a single neurotransmitter.
The first hypothesis was championed by Walter Bradford Cannon and Arturo Rosenblueth,[1] who interpreted many experiments to then propose that there were two neurotransmitter substances, which they called sympathin E (for 'excitation') and sympathin I (for 'inhibition').
The second hypothesis found support from 1906 to 1913, when Henry Hallett Dale explored the effects of adrenaline (which he called adrenine at the time), injected into animals, on blood pressure. Usually, adrenaline would increase the blood pressure of these animals. Although, if the animal had been exposed to ergotoxine, the blood pressure decreased.[2][3] He proposed that the ergotoxine caused "selective paralysis of motor myoneural junctions" (i.e. those tending to increase the blood pressure) hence revealing that under normal conditions that there was a "mixed response", including a mechanism that would relax smooth muscle and cause a fall in blood pressure. This "mixed response", with the same compound causing either contraction or relaxation, was conceived of as the response of different types of junctions to the same compound.
This line of experiments were developed by several groups, including DT Marsh and colleagues,[4] who in February 1948 showed that a series of compounds structurally related to adrenaline could also show either contracting or relaxing effects, depending on whether or not other toxins were present. This again supported the argument that the muscles had two different mechanisms by which they could respond to the same compound. In June of that year, Raymond Ahlquist, Professor of Pharmacology at Medical College of Georgia, published a paper concerning adrenergic nervous transmission.[5] In it, he explicitly named the different responses as due to what he called
Categories
[edit]The mechanism of adrenoreceptors. Adrenaline or noradrenaline are receptor ligands to either
α receptors are subdivided intoα 1 (a Gq coupled receptor) andα 2 (a Gi coupled receptor)[7]α 1 has 3 subtypes:α 1A,α 1B andα 1D[a]α 2 has 3 subtypes:α 2A,α 2B andα 2C
β receptors are subdivided intoβ 1,β 2 andβ 3. All 3 are coupled to Gs proteins, butβ 2 andβ 3 also couple to Gi[7]
Gi and Gs are linked to adenylyl cyclase. Agonist binding thus causes a rise in the intracellular concentration of the second messenger (Gi inhibits the production of cAMP) cAMP. Downstream effectors of cAMP include cAMP-dependent protein kinase (PKA), which mediates some of the intracellular events following hormone binding.
Roles in circulation
[edit]Epinephrine (adrenaline) reacts with both
Subtypes
[edit]Smooth muscle behavior is variable depending on anatomical location. Smooth muscle contraction/relaxation is generalized below. One important note is the differential effects of increased cAMP in smooth muscle compared to cardiac muscle. Increased cAMP will promote relaxation in smooth muscle, while promoting increased contractility and pulse rate in cardiac muscle.
α receptors
[edit]- vasoconstriction[13]
- decreased flow of smooth muscle in gastrointestinal tract[14]
Subtype unspecific
α 1 receptor
[edit]Actions of the
- ureter
- vas deferens
- hair (arrector pili muscles)
- uterus (when pregnant)
- urethral sphincter
- urothelium and lamina propria[18]
- bronchioles (although minor relative to the relaxing effect of
β 2 receptor on bronchioles) - blood vessels of ciliary body and (stimulation of dilator pupillae muscles of iris causes mydriasis)
Actions also include glycogenolysis and gluconeogenesis from adipose tissue and liver; secretion from sweat glands and Na+ reabsorption from kidney.[19]
- hypertension – decrease blood pressure by decreasing peripheral vasoconstriction
- benign prostate hyperplasia – relax smooth muscles within the prostate thus easing urination
α 2 receptor
[edit]The
Actions of the
- decreased insulin release from the pancreas[19]
- increased glucagon release from the pancreas
- contraction of sphincters of the GI-tract
- negative feedback in the neuronal synapses - presynaptic inhibition of norepinephrine release in CNS
- increased platelet aggregation
- decreases peripheral vascular resistance
- hypertension – decrease blood pressure-raising actions of the sympathetic nervous system
- impotence – relax penile smooth muscles and ease blood flow
- depression – enhance mood by increasing norepinephrine secretion
β receptors
[edit]Subtype unspecific
- heart failure – increase cardiac output acutely in an emergency
- circulatory shock – increase cardiac output thus redistributing blood volume
- anaphylaxis – bronchodilation
Subtype unspecific
- heart arrhythmia – decrease the output of sinus node thus stabilizing heart function
- coronary artery disease – reduce heart rate and hence increasing oxygen supply
- heart failure – prevent sudden death related to this condition,[7] which is often caused by ischemias or arrhythmias[21]
- hyperthyroidism – reduce peripheral sympathetic hyper-responsiveness
- migraine – reduce number of attacks
- stage fright – reduce tachycardia and tremor
- glaucoma – reduce intraocular pressure
β 1 receptor
[edit]Actions of the
- increase cardiac output by increasing heart rate (positive chronotropic effect), conduction velocity (positive dromotropic effect), stroke volume (by enhancing contractility – positive inotropic effect), and rate of relaxation of the myocardium, by increasing calcium ion sequestration rate (positive lusitropic effect), which aids in increasing heart rate
- increase renin secretion from juxtaglomerular cells of the kidney[22]
- increase ghrelin secretion from the stomach[23]
β 2 receptor
[edit]Actions of the
- smooth muscle relaxation throughout many areas of the body, e.g. in bronchi (bronchodilation, see salbutamol),[19] GI tract (decreased motility), veins (vasodilation of blood vessels), especially those to skeletal muscle (although this vasodilator effect of norepinephrine is relatively minor and overwhelmed by
α adrenoceptor-mediated vasoconstriction)[24] - lipolysis in adipose tissue[25]
- anabolism in skeletal muscle[26][27]
- uptake of potassium into cells[28]
- relax non-pregnant uterus
- relax detrusor urinae muscle of bladder wall
- dilate arteries to skeletal muscle
- glycogenolysis and gluconeogenesis
- stimulates insulin secretion[29]
- contract sphincters of GI tract
- thickened secretions from salivary glands[19]
- inhibit histamine-release from mast cells
- involved in brain - immune communication[30]
- asthma and COPD – reduce bronchial smooth muscle contraction thus dilating the bronchus
- hyperkalemia – increase cellular potassium intake
- preterm birth – reduce uterine smooth muscle contractions[31]
β 3 receptor
[edit]Actions of the
- increase of lipolysis in adipose tissue
- relax the bladder
See also
[edit]- Beta adrenergic receptor kinase
- Beta adrenergic receptor kinase-2
- Acetylcholine receptor (Cholinergic receptor)
Notes
[edit]References
[edit]- ^ Cannon WB, Rosenbluth A (31 May 1933). "Studies On Conditions Of Activity In Endocrine Organs XXVI: Sympathin E and Sympathin I". American Journal of Physiology. 104 (3): 557–574. doi:10.1152/ajplegacy.1933.104.3.557.
- ^ Dale HH (May 1906). "On some physiological actions of ergot". The Journal of Physiology. 34 (3): 163–206. doi:10.1113/jphysiol.1906.sp001148. PMC 1465771. PMID 16992821.
- ^ Dale HH (Jun 1913). "On the action of ergotoxine; with special reference to the existence of sympathetic vasodilators". The Journal of Physiology. 46 (3): 291–300. doi:10.1113/jphysiol.1913.sp001592. PMC 1420444. PMID 16993202.
- ^ Marsh DT, Pelletier MH, Rose CA (Feb 1948). "The comparative pharmacology of the N-alkyl-arterenols". The Journal of Pharmacology and Experimental Therapeutics. 92 (2): 108–20. PMID 18903395.
- ^ Ahlquist RP (Jun 1948). "A study of the adrenotropic receptors". The American Journal of Physiology. 153 (3): 586–600. doi:10.1152/ajplegacy.1948.153.3.586. PMID 18882199. S2CID 1518772.
- ^ Drill VA (1954). Pharmacology in medicine: a collaborative textbook. New York: McGraw-Hill.
- ^ a b c d e f g h i j k l m n o Perez, Dianne M. (2006). The adrenergic receptors in the 21st century. Totowa, New Jersey: Humana Press. pp. 54, 129–134. ISBN 978-1588294234. LCCN 2005008529. OCLC 58729119.
- ^ Zwieten, Van; A, P. (1986). "Interaction Between
α andβ -Adrenoceptor-Mediated Cardiovascular Effects". Journal of Cardiovascular Pharmacology. 8: S21-8. doi:10.1097/00005344-198608004-00004. ISSN 0160-2446. PMID 2427848. - ^ a b c d e Rang HP, Ritter JM, Flower RJ, Henderson G (2016). Rang and Dale's pharmacology (8th ed.). United Kingdom: Elsevier. p. 179. ISBN 9780702053627. OCLC 903083639.
- ^ Prischich, Davia; Gomila, Alexandre M. J.; Milla-Navarro, Santiago; Sangüesa, Gemma; Diez-Alarcia, Rebeca; Preda, Beatrice; Matera, Carlo; Batlle, Montserrat; Ramírez, Laura; Giralt, Ernest; Hernando, Jordi; Guasch, Eduard; Meana, J. Javier; de la Villa, Pedro; Gorostiza, Pau (2020). "Adrenergic modulation with photochromic ligands". Angewandte Chemie International Edition. 60 (7): 3625–3631. doi:10.1002/anie.202010553. hdl:2434/778579. ISSN 1433-7851. PMID 33103317.
- ^ Tesmer JJ, et al. (2012-09-21). "Paroxetine is a direct inhibitor of g protein-coupled receptor kinase 2 and increases myocardial contractility". ACS Chemical Biology. 7 (11): 1830–1839. doi:10.1021/cb3003013. ISSN 1554-8929. PMC 3500392. PMID 22882301.
- ^ Nisoli E, Tonello C, Landi M, Carruba MO (1996). "Functional studies of the first selective beta 3-adrenergic receptor antagonist SR 59230A in rat brown adipocytes". Molecular Pharmacology. 49 (1): 7–14. PMID 8569714.
- ^ Elliott J (1997). "Alpha-adrenoceptors in equine digital veins: evidence for the presence of both alpha1 and alpha2-receptors mediating vasoconstriction". Journal of Veterinary Pharmacology and Therapeutics. 20 (4): 308–17. doi:10.1046/j.1365-2885.1997.00078.x. PMID 9280371.
- ^ Sagrada A, Fargeas MJ, Bueno L (1987). "Involvement of alpha-1 and alpha-2 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.
- ^ Smith RS, Weitz CJ, Araneda RC (Aug 2009). "Excitatory actions of noradrenaline and metabotropic glutamate receptor activation in granule cells of the accessory olfactory bulb". Journal of Neurophysiology. 102 (2): 1103–14. doi:10.1152/jn.91093.2008. PMC 2724365. PMID 19474170.
- ^ Schmitz JM, Graham RM, Sagalowsky A, Pettinger WA (1981). "Renal alpha-1 and alpha-2 adrenergic receptors: biochemical and pharmacological correlations". The Journal of Pharmacology and Experimental Therapeutics. 219 (2): 400–6. PMID 6270306.
- ^ Circulation & Lung Physiology I Archived 2011-07-26 at the Wayback Machine M.A.S.T.E.R. Learning Program, UC Davis School of Medicine
- ^ Moro C, Tajouri L, Chess-Williams R (2013). "Adrenoceptor function and expression in bladder urothelium and lamina propria". Urology. 81 (1): 211.e1–7. doi:10.1016/j.urology.2012.09.011. PMID 23200975.
- ^ a b c d Fitzpatrick D, Purves D, Augustine G (2004). "Table 20:2". Neuroscience (3rd ed.). Sunderland, Mass: Sinauer. ISBN 978-0-87893-725-7.
- ^ Qin K, Sethi PR, Lambert NA (2008). "Abundance and stability of complexes containing inactive G protein-coupled receptors and G proteins". FASEB Journal. 22 (8): 2920–7. doi:10.1096/fj.08-105775. PMC 2493464. PMID 18434433.
- ^ Ørn S, Dickstein K (2002-04-01). "How do heart failure patients die?". European Heart Journal Supplements. 4 (Suppl D): D59–D65. doi:10.1093/oxfordjournals.ehjsupp.a000770.
- ^ Kim SM, Briggs JP, Schnermann J (February 2012). "Convergence of major physiological stimuli for renin release on the Gs-alpha/cyclic adenosine monophosphate signaling pathway". Clinical and Experimental Nephrology. 16 (1): 17–24. doi:10.1007/s10157-011-0494-1. PMC 3482793. PMID 22124804.
- ^ Zhao TJ, Sakata I, Li RL, Liang G, Richardson JA, Brown MS, et al. (Sep 2010). "Ghrelin secretion stimulated by {beta}1-adrenergic receptors in cultured ghrelinoma cells and in fasted mice". Proceedings of the National Academy of Sciences of the United States of America. 107 (36): 15868–73. Bibcode:2010PNAS..10715868Z. doi:10.1073/pnas.1011116107. PMC 2936616. PMID 20713709.
- ^ Klabunde R. "Adrenergic and Cholinergic Receptors in Blood Vessels". Cardiovascular Physiology. Retrieved 5 May 2015.
- ^ Large V, Hellström L, Reynisdottir S, et al. (1997). "Human beta-2 adrenoceptor gene polymorphisms are highly frequent in obesity and associate with altered adipocyte beta-2 adrenoceptor function". The Journal of Clinical Investigation. 100 (12): 3005–13. doi:10.1172/JCI119854. PMC 508512. PMID 9399946.
- ^ Kline WO, Panaro FJ, Yang H, Bodine SC (2007). "Rapamycin inhibits the growth and muscle-sparing effects of clenbuterol". Journal of Applied Physiology. 102 (2): 740–7. doi:10.1152/japplphysiol.00873.2006. PMID 17068216. S2CID 14292004.
- ^ Kamalakkannan G, Petrilli CM, George I, et al. (2008). "Clenbuterol increases lean muscle mass but not endurance in patients with chronic heart failure". The Journal of Heart and Lung Transplantation. 27 (4): 457–61. doi:10.1016/j.healun.2008.01.013. PMID 18374884.
- ^ Basic & Clinical Pharmacology. United States of America: MCGraw-Hill Education. 2018. p. 148. ISBN 978-1-259-64115-2.
- ^ Santulli G, Lombardi A, Sorriento D, Anastasio A, Del Giudice C, Formisano P, Béguinot F, Trimarco B, Miele C, Iaccarino G (March 2012). "Age-related impairment in insulin release: the essential role of
β (2)-adrenergic receptor". Diabetes. 61 (3): 692–701. doi:10.2337/db11-1027. PMC 3282797. PMID 22315324. - ^ Elenkov IJ, Wilder RL, Chrousos GP, Vizi ES (December 2000). "The sympathetic nerve--an integrative interface between two supersystems: the brain and the immune system". Pharmacological Reviews. 52 (4): 595–638. PMID 11121511.
- ^ Haas DM, Benjamin T, Sawyer R, Quinney SK (2014). "Short-term tocolytics for preterm delivery - current perspectives". International Journal of Women's Health. 6: 343–9. doi:10.2147/IJWH.S44048. PMC 3971910. PMID 24707187.
- ^ Hieble JP, Bylund DB, Clarke DE, Eikenburg DC, Langer SZ, Lefkowitz RJ, Minneman KP, Ruffolo RR (June 1995). "International Union of Pharmacology. X. Recommendation for nomenclature of alpha 1-adrenoceptors: consensus update". Pharmacological Reviews. 47 (2): 267–70. PMID 7568329.
Further reading
[edit]- Rang HP, Dale MM, Ritter JM, Flower RJ (2007). "Chapter 11: Noradrenergic transmission". Rang and Dale's Pharmacology (6th ed.). Elsevier Churchill Livingstone. pp. 169–170. ISBN 978-0-443-06911-6.