Adrenergic Receptor

Aka: Adrenergic Receptor, Catecholamine, Sympathomimetic, Adrenergic Agonist, Dopaminergic Receptor

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II. Definitions

  1. Sympathetic Nervous System
    1. Part of Autonomic Nervous System with activity that typically counters the Parasympathetic Nervous System
    2. Energy expending (catabolic) system, activated in stressful situations (e.g. emergency fight or flight)
      1. Contrast with the Parasympathetic Nervous System, an energy conserving system activated at times of rest
  2. Catecholamines
    1. Catecholamines act as Sympathetic System neuromodulators, binding adrenergic and Dopaminergic Receptors
    2. Catecholamines contain a catechol (benzene ring with 2 hydroxyl groups) derived from the Amino AcidTyrosine
    3. Endogenous Catecholamines are synthesized in the Adrenal Gland and postganglionic sympathetic Neurons
    4. Catecholamines include Epinephrine, Norepinephrine and Dopamine
  3. Sympathomimetics (Adrenergic Agonist)
    1. Sympathomimetics are agents that mimic the activity of postganglionic sympathetic Neurons
    2. Sympathomimetics include exogenous Catecholamines, as well as other agents with sympathetic activity
    3. Direct Sympathomimetics bind specific Adrenergic Receptors (a1, a2, b1, b2, d1-5) to trigger sympathetic activity
    4. Indirect Sympathomimetics enter the presynaptic Neuron and displace Norepinephrine from their storage vessicles
    5. Mixed Sympathomimetics act both indirectly (Norepinephrine displacement) AND directly (Adrenergic Receptor binding)

III. Physiology: Images

  1. sympatheticNervousSystem.jpg
  2. AdrenalFunction.png
  3. autonomicSynapse.png

IV. Physiology: Receptor Types

  1. Alpha Adrenergic Receptor
    1. Alpha 1 Adrenergic Agonists Vasoconstrict, increase myocardial contractility, decrease Heart Rate, dilate pupil, constrict anal sphincter
    2. Peripheral Alpha 2 Adrenergic Agonists have mixed vessel effects, relaxe GI Smooth Muscle and stimulate fat cell lipolysis
    3. Central Alpha 2 Adrenergic Agonists vasodilate peripheral vessels
  2. Beta Adrenergic Receptor
    1. Beta 1 Adrenergic Agonists increase myocardial contractility and Heart Rate, and increases renin release and fat cell lipolysis
    2. Beta 2 Adrenergic Agonists vasodilate, bronchodilate, relax Bladder wall and stimulate liver Gluconeogenesis and glycogenolysis
  3. Dopaminergic Receptor
    1. Central Dopaminergic Agonists effect motion, cognition, emotion, motivation and nutritional intake
    2. Peripheral Dopaminergic Agonists increase cardiac contractility, vasodilation and diuresis

V. Preparations: Sympathetic Agents

  1. Catecholamines: Medical and endogenous agents with Direct Sympathetic Activity
    1. Background: Catecholamines with Direct Sympathetic Activity
      1. Catecholamines, on binding alpha and beta receptors, stimulate specific Neuron second messenger release (e.g. cAMP, Inositol)
      2. These second messengers exert inta-Neuron effects associated with the receptor stimulated (a1, a2, b1, b2, d1-d5)
      3. Catecholamines are rapidly metabolized by the enzymes COMT and MAO, and have a relatively short duration of action
    2. Alpha Adrenergic Agonists (also have beta effects as well)
      1. Epinephrine
        1. First line agent in ACLS (VT/VFib, PEA, Symptomatic Bradycardia), Anaphylaxis, Status Asthmaticus
        2. Vasoconstriction (a1), Tachycardia and increased contractility (b1) and bronchodilation (b2)
        3. Increased Serum Glucose via glycogenolysis and Gluconeogenesis (b2) and fat breakdown (b1)
      2. Norepinephrine
        1. First line Vasopressor in fluid refractory Hypotension (esp. Septic Shock)
        2. Strong Vasoconstriction and increased arterial pressure (a1) and reflex Bradycardia
        3. Unlike Epinephrine, only small effects on contractility and NO beta effect (no bronchodilation or metabolic effects)
    3. Beta Adrenergic Agonists
      1. Isoproterenol
        1. Pure Beta activity, with strong vasodilation, increased Heart Rate and contractility, and bronchodilation
        2. Increased Serum Glucose via glycogenolysis and Gluconeogenesis (b2) and fat breakdown (b1)
      2. Dobutamine
        1. Synthetic Dopamine derivative
        2. Primarily B1 activity with increased cardiac contractility, and minimal increase in Heart Rate
        3. Only weak B2 (no bronchodilation), and minimal alpha activity (no significant change in vascular resistance)
    4. Dopaminergic Agonists
      1. Dopamine
        1. Dopaminergic and B1 activity
        2. Has largely been replaced by Norepinephrine as a Vasopressor in adult shock (but still used in pediatric shock)
        3. Increases cardiac contractility, systolic Blood Pressure and to a lesser extent Heart Rate
        4. Dose related effects
          1. Low dose (renal dose Dopamine): Arteriole constriction in sites other than brain and Kidney, increasing GFR
          2. High dose: Diffuse Vasoconstriction with decreased renal perfusion and decreased GFR
  2. Non-Catecholamines: Medical agents with Direct Sympathetic Activity
    1. Background: Non-Catecholamines with Direct Sympathetic Activity
      1. Similar activity to Catecholamines by acting as direct Agonists, binding alpha and beta receptors
      2. However, non-Catecholamines have longer duration of action, as they are not metabolized by COMT and MAO
    2. Alpha Adrenergic Agonists
      1. Phenylephrine
        1. Frequent use as a Push Dose Pressor in Anesthesia for Hypotension
        2. Strong Vasopressor with increased systolic Blood Pressure and reflex Bradycardia
        3. Also used as a nasal Decongestant (neosynephrine)
    3. Beta 2 Adrenergic Agonists
      1. Bronchodilators (e.g. Albuterol, Terbutaline, Salmeterol, Pirbuterol)
        1. Primarily B2 activity with bronchodilation, but mild B1 activity results in Tachycardia
  3. Non-Catecholamines: Illicit and non-medical agents with Indirect Sympathetic Activity
    1. Background: Indirect Sympathomimetics
      1. Unlike direct sympathetic Agonists, these agents do not bind Adrenergic Receptors
      2. Indirect Sympathomimetics enter presynaptic Neuron and displace Norepinephrine from their storage vessicles
    2. Indirect Sympathomimetics
      1. Cocaine
        1. Blocks Monoamine Reuptake at nerve terminal
        2. Effects include Tachycardia, Hypertension, hyperthermia, Mydriasis, Seizures
      2. Amphetamines (MDMA or Ecstasy, Methamphetamine)
        1. Vasoconstriction, Hypertension, increased cardiac contractility, Tachycardia (or reflex decrease in Heart Rate)
        2. Amphetamines are used medically in Narcolepsy and Attention Deficit Disorder
      3. Caffeine
        1. Nonselective, Competitive Inhibition of Adenosine receptors
        2. Increases diastolic Blood Pressure and Epinephrine levels
  4. Non-Catecholamines: Illicit and non-medical agents with Mixed Sympathetic Activity
    1. Background: Mixed Sympathomimetics
      1. Mixed Sympathomimetics act both indirectly (Norepinephrine displacement) AND directly (Adrenergic Receptor binding)
    2. Mixed Sympathomimetics
      1. Synthetic Cathinones (Psychoactive Bath Salts)
        1. Inhibits Norepinephrine, Serotonin and Dopamine reuptake, resulting in increased Neurotransmitter levels
        2. Results in Sympathomimetic and Hallucinogenic effects (similar to Amphetamines)
      2. Ephedrine (Ephedra)
        1. Vasoconstriction, increased Blood Pressure, and cardiac contractility, no Heart Rate effect (indirect NE release)
        2. Bronchodilation (direct Sympathomimetic effect)
      3. Nicotine
        1. Acts at acetylcholine Nicotinic Receptors on peripheral postganglionic Sympathetic Nerves
        2. Stimulates Catecholamine release from Adrenal Medulla
        3. Sympathomimetic effects include Vasoconstriction, increased contractility and Heart Rate

VI. Preparations: Sympathetic Antagonists

  1. Central Adrenergic Agonist (presynaptic, Antagonize Sympathetic System, Antihypertensive agents)
    1. Clonidine
    2. Guanfacine
    3. Methyldopa (Aldomet)
  2. Peripheral Presynaptic Adrenergic Antagonist (Antihypertensive)
    1. Guanethidine
    2. Reserpine
  3. Postsynaptic Alpha Adrenergic Antagonist
    1. Selective Alpha-1a Antagonists: Prostate specific agents (e.g. Tamsulosin)
    2. Non-Selective Agents: Antihypertensives: (e.g. Terazosin, Doxazosin, Prazosin)
  4. Beta Adrenergic Antagonist (Beta Blocker)
    1. Beta-1 Selective Adrenergic Blockade (e.g. Metoprolol, Atenolol)
    2. Beta-1 and Beta-2 Adrenergic Blockade (e.g. Propranolol, Nadolol, Sotalol)
    3. Combined Alpha-1, Beta-1 and Beta-2 Adrenergic Blockade (e.g. Labetalol, Carvedilol)

VII. References

  1. Olson (2020) Clinical Pharmacology, Medmasters, Miami, p. 13-33
  2. Goldstein (2010) Clin Auton Res 20(6):331-52 +PMID: 20623313 [PubMed]

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Related Studies

Ontology: Adrenergic Agonists (C0001648)

Definition (NCI) Any agent that binds to and activates any of the adrenergic receptors.
Definition (MSH) Drugs that bind to and activate adrenergic receptors.
Concepts Pharmacologic Substance (T121)
MSH D000322
SnomedCT 86308005
English Adrenergic Receptor Agonists, Agonists, Adrenergic Receptor, Receptor Agonists, Adrenergic, Adrenergic Agonist, Adrenergic Receptor Agonist, Agonist, Adrenergic, Agonist, Adrenergic Receptor, Agonists, Adrenergic, Receptor Agonist, Adrenergic, ADREN RECEPT AGON, ADREN RECEPT AG, ADREN AGON, ADREN AG, RECEPT AGON ADREN, adrenergic receptor agonists, adrenomimetic drugs, Adrenergic Agonists, agonists adrenergic, adrenergic agonist, adrenergic agonists, adrenomimetic, Adrenomimetics, Adrenoreceptor stimulant
French Adrénomimétiques, Sympathomimétiques directs, Agoniste adrénergique, Agoniste des récepteurs adrénergiques, Agonistes adrénergiques, Agonistes des récepteurs adrénergiques
Swedish Adrenerga stimulerare
Czech receptory adrenergní - agonisté
Finnish Adrenergiset agonistit
Italian Adrenomimetici, Agonisti del recettore adrenergico, Agonista del recettore adrenergico, Agonista adrenergico, Agonisti adrenergici
Russian ADRENERGICHESKIE AGONISTY, ADRENERGICHESKIKH RETSEPTOROV AGONISTY, ADRENORETSEPTOROV AGONISTY, АДРЕНЕРГИЧЕСКИЕ АГОНИСТЫ, АДРЕНЕРГИЧЕСКИХ РЕЦЕПТОРОВ АГОНИСТЫ, АДРЕНОРЕЦЕПТОРОВ АГОНИСТЫ
Japanese アドレナリン作動物質, アドレナリン作用性受容体作用物質, アドレナリン作動性物質, アドレナリン作用性受容体作用剤, アドレナリン作動薬, アドレナリン作動性薬, アドレナリン作用性受容器作用物質, アドレナリンアゴニスト, アドレナリン作動剤
Polish Agoniści adrenergiczni
German Adrenerge Agonisten
Portuguese Adrenomiméticos, Agonistas Adrenérgicos
Spanish Adrenomiméticos, Agonistas Adrenérgicos
Derived from the NIH UMLS (Unified Medical Language System)

Ontology: Catecholamines (C0007412)

Definition (NCI_NCI-GLOSS) A type of neurohormone (a chemical that is made by nerve cells and used to send signals to other cells). Catecholamines are important in stress responses. High levels cause high blood pressure which can lead to headaches, sweating, pounding of the heart, pain in the chest, and anxiety. Examples of catecholamines include dopamine, epinephrine (adrenaline), and norepinephrine (noradrenaline).
Definition (NCI) A group of sympathetic amines containing a catechol group derived from the amino acid tyrosine. Catecholamines are hormones and neuromodulators synthesized in the chromaffin cells of the adrenal glands and the postganglionic fibers of the sympathetic nervous system in response to stress. Examples of catecholamines are epinephrine (adrenaline), norepinephrine (noradrenaline) and dopamine, all of which participate in a wide variety of functions throughout the body.
Definition (MSH) A general class of ortho-dihydroxyphenylalkylamines derived from tyrosine.
Definition (CSP) any of various substances that contain a benzene ring with two adjacent hydroxyl groups and a side chain of ethylamine and that function as hormones or neurotransmitters or both; examples are dopamine, norepinephrine, and epinephrine.
Concepts Neuroreactive Substance or Biogenic Amine (T124) , Pharmacologic Substance (T121)
MSH D002395
SnomedCT 34582008
LNC LP15090-1, MTHU003446
English Catecholamines, Sympathins, Coumel, Catecholamines [Chemical/Ingredient], catecholamines, sympathin, coumel, catecholamine, Catecholamine, Total catecholamines, Catecholamine (substance), Catecholamine, NOS
Swedish Katekolaminer
Czech katecholaminy
Finnish Katekoliamiinit
Italian Simpatine, Catecolamine
Russian SIMPATINY, KATEKHOLAMINY, КАТЕХОЛАМИНЫ, СИМПАТИНЫ
Japanese カテコールアミン, シンパチン, カテコラミン
Croatian KATEKOLAMINI
Polish Sympatyny, Katecholaminy, Aminy katecholowe
Norwegian Not Translated[Catecholamines]
Spanish catecolamina (sustancia), catecolamina, Catecolaminas, Simpatinas
French Catécholamines
German Catecholamine, Katecholamine, Sympathine
Portuguese Catecolaminas, Simpatinas
Derived from the NIH UMLS (Unified Medical Language System)

Ontology: Adrenergic Receptor (C0034783)

Definition (MSH) Cell-surface proteins that bind epinephrine and/or norepinephrine with high affinity and trigger intracellular changes. The two major classes of adrenergic receptors, alpha and beta, were originally discriminated based on their cellular actions but now are distinguished by their relative affinity for characteristic synthetic ligands. Adrenergic receptors may also be classified according to the subtypes of G-proteins with which they bind; this scheme does not respect the alpha-beta distinction.
Definition (PSY) Class of neural receptors that are sensitive to the neurotransmitters epinephrine and norepinephrine.
Definition (CSP) family of G protein coupled receptors sensitive to epinephrine, norepinephrine, and their analogs, found in smooth and cardiac muscle, autonomic ganglia, brain, and elsewhere.
Concepts Receptor (T192) , Amino Acid, Peptide, or Protein (T116)
MSH D011941
SnomedCT 59208001
English Adrenergic Receptor, Adrenergic Receptors, Adrenoceptors, Receptor, Adrenergic, Receptors, Adrenergic, Epinephrine Receptors, Receptors, Epinephrine, adrenergic receptor, RECEPT ADREN, RECEPT EPINEPHRINE, EPINEPHRINE RECEPT, ADREN RECEPT, Adrenergic receptor site, Receptors, Adrenergic [Chemical/Ingredient], adrenergic receptors, adrenoceptors, adrenergic receptor sites, adrenoceptor, Adrenaline--Receptors, Adrenergic receptor (substance), Adrenergic receptor, Adrenaline Receptors, Receptors (Adrenergic), adrenoreceptor
Swedish Receptorer, adrenerga
Finnish Adrenergiset reseptorit
Italian Adrenorecettori, Recettore adrenergico, Recettori dell'epinefrina, Recettori adrenergici
Russian ADRENERGICHESKIE RETSEPTORY, RETSEPTORY ADRENERGICHESKIE, ADRENORETSEPTORY, RETSEPTORY ADRENALINA, RETSEPTORY NOREPINEFRINA, RETSEPTORY EPINEFRINA, RETSEPTORY NORADRENALINA, АДРЕНЕРГИЧЕСКИЕ РЕЦЕПТОРЫ, АДРЕНОРЕЦЕПТОРЫ, РЕЦЕПТОРЫ АДРЕНАЛИНА, РЕЦЕПТОРЫ АДРЕНЕРГИЧЕСКИЕ, РЕЦЕПТОРЫ НОРАДРЕНАЛИНА, РЕЦЕПТОРЫ НОРЭПИНЕФРИНА, РЕЦЕПТОРЫ ЭПИНЕФРИНА
Japanese 受容体-アドレナリン作用性, 受容体-ノルエピネフリン, エピネフリン受容体, 交感神経受容体, 受容体-アドレナリン, ノルエピネフリン受容体, アドレナリン作用性受容体, アドレナリン受容体
Croatian RECEPTORI, ADRENERGIČKI
French Adrénorécepteurs, Récepteurs de l'adrénaline, Récepteurs de l'épinéphrine, Récepteurs à l'adrénaline, Récepteurs adrénergiques, Récepteurs à l'épinéphrine
Czech receptory epinefrinu, adrenergní receptory, receptory adrenergní, adrenoreceptory
Polish Receptory adrenergiczne
Spanish receptor adrenérgico (sustancia), receptor adrenérgico, Adrenorreceptores, Receptores de Epinefrina, Receptores Adrenérgicos
German Adrenerge Rezeptoren, Adrenorezeptoren, Rezeporen, Epinephrin-, Rezeptoren, adrenerge
Portuguese Adrenoceptores, Receptores Adrenérgicos, Receptores da Epinefrina
Derived from the NIH UMLS (Unified Medical Language System)

Ontology: Sympathomimetics (C0039052)

Definition (MSH) Drugs that mimic the effects of stimulating postganglionic adrenergic sympathetic nerves. Included here are drugs that directly stimulate adrenergic receptors and drugs that act indirectly by provoking the release of adrenergic transmitters.
Concepts Pharmacologic Substance (T121)
MSH D013566
SnomedCT 349942009, 86308005, 372884008
LNC LP18076-7, MTHU003355
English Agents, Sympathomimetic, Drugs, Sympathomimetic, Sympathomimetic Agents, Sympathomimetic Drugs, Sympathomimetic compound, sympathomimetic agent, sympathomimetics (medication), sympathomimetics, sympathomimetic drug, sympathomimetic drugs, sympathomimetic agents, sympathomimetic, Sympathomimetic compound (product), Sympathomimetic agents, Sympathomimetic, Sympathomimetic agent (product), Sympathomimetic agent (substance), Sympathomimetic agent, Sympathomimetics, Sympathomimetic agent, NOS, Sympathomimetic compound (substance)
French Médicaments sympathomimétiques, Agents sympathomimétiques, Sympathomimétiques
Swedish Sympatomimetika
Czech sympatomimetika
Finnish Sympatomimeetit
Italian Farmaci simpatomimetici, Sostanze simpatomimetiche, Simpatomimetici
Russian SIMPATOMIMETICHESKIE SREDSTVA, AMINY SIMPATOMIMETICHESKIE, АМИНЫ СИМПАТОМИМЕТИЧЕСКИЕ, СИМПАТОМИМЕТИЧЕСКИЕ СРЕДСТВА
Japanese 交感神経効果薬, 交感神経作動薬, 交感神経様作用薬, 交感神経興奮性アミン, 交感神経作用薬, 交感神経刺激薬, アミン-交感神経興奮性, 交感神経効果剤
Croatian SIMPATOMIMETICI
Polish Sympatomimetyki, Środki pobudzające układ współczulny, Leki sympatykomimetyczne
Spanish compuesto simpaticomimético (producto), compuesto simpaticomimético, Efecto Simpatomimético, agente simpaticomimético (producto), agente simpaticomimético (sustancia), agente simpaticomimético, simpaticomimético, Simpatomiméticos
Portuguese Efeito Simpatomimético, Simpatomiméticos
German Adrenerge Substanzen, Sympathomimetika
Derived from the NIH UMLS (Unified Medical Language System)

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