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Encyclopedia > Adenosine
Adenosine
Systematic (IUPAC) name
(2R,3R,4R,5R)-2-(6-aminopurin-9-yl)- 5-(hydroxymethyl)oxolane-3,4-diol
Identifiers
CAS number 58-61-7
ATC code C01EB10
PubChem 60961
DrugBank APRD00132
Chemical data
Formula C10H13N5O4 
Mol. mass 267.242 g/mol
SMILES search in eMolecules, PubChem
Pharmacokinetic data
Bioavailability Rapidly cleared from circulation via cellular uptake
Protein binding No
Metabolism Rapidly converted to inosine and adenosine monophosphate
Half life cleared plasma <30 seconds - half life <10 seconds
Excretion can leave cell intact or can be degraded to hypoxanthine, xanthine, and ultimately uric acid
Therapeutic considerations
Pregnancy cat.

C Image File history File links No higher resolution available. ... IUPAC nomenclature is a system of naming chemical compounds and of describing the science of chemistry in general. ... CAS registry numbers are unique numerical identifiers for chemical compounds, polymers, biological sequences, mixtures and alloys. ... The Anatomical Therapeutic Chemical Classification System is used for the classification of drugs. ... A section of the Anatomical Therapeutic Chemical Classification System. ... PubChem is a database of chemical molecules. ... The DrugBank database available at the University of Alberta is a unique bioinformatics and cheminformatics resource that combines detailed drug (i. ... A chemical formula is a concise way of expressing information about the atoms that constitute a particular chemical compound. ... For other uses, see Carbon (disambiguation). ... General Name, Symbol, Number hydrogen, H, 1 Chemical series nonmetals Group, Period, Block 1, 1, s Appearance colorless Atomic mass 1. ... General Name, symbol, number nitrogen, N, 7 Chemical series nonmetals Group, period, block 15, 2, p Appearance colorless gas Standard atomic weight 14. ... General Name, symbol, number oxygen, O, 8 Chemical series nonmetals, chalcogens Group, period, block 16, 2, p Appearance colorless (gas) very pale blue (liquid) Standard atomic weight 15. ... The molecular mass (abbreviated Mr) of a substance, formerly also called molecular weight and abbreviated as MW, is the mass of one molecule of that substance, relative to the unified atomic mass unit u (equal to 1/12 the mass of one atom of carbon-12). ... The simplified molecular input line entry specification or SMILES is a specification for unambiguously describing the structure of chemical molecules using short ASCII strings. ... In pharmacology, bioavailability is used to describe the fraction of an administered dose of unchanged drug that reaches the systemic circulation, one of the principal pharmacokinetic properties of drugs. ... A drugs efficacy may be affected by the degree to which it binds to the proteins within blood plasma. ... Drug metabolism is the metabolism of drugs, their biochemical modification or degradation, usually through specialized enzymatic systems. ... It has been suggested that Effective half-life be merged into this article or section. ... The kidneys are important excretory organs in vertebrates. ... The pregnancy category of a pharmaceutical agent is an assessment of the risk of fetal injury due to the pharmaceutical, if it is used as directed by the mother during pregnancy. ...

Legal status

Australia - Legal; UK - Legal; US - Rx only The regulation of therapeutic goods, that is drugs and therapeutic devices, varies by jurisdiction. ...

Routes IV or injection

Adenosine is a nucleoside composed of adenine attached to a ribose (ribofuranose) moiety via a β-N9-glycosidic bond. In pharmacology and toxicology, a route of administration is the path by which a drug, fluid, poison or other substance is brought into contact with the body. ... Nucleosides are glycosylamines made by attaching a nucleobase (often reffered to simply as bases) to a ribose ring. ... For the programming language Adenine, see Adenine (programming language). ... Ribose Ribose, primarily seen as D-ribose, is an aldopentose — a monosaccharide containing five carbon atoms, and including an aldehyde functional group. ... A ribofuranose is an alternative name to the ring structure of ribose. ... In chemistry, a glycosidic bond is a certain type of functional group that joins a carbohydrate (sugar) molecule to an alcohol, which may be another carbohydrate. ...


Adenosine plays an important role in biochemical processes, such as energy transfer - as adenosine triphosphate (ATP) and adenosine diphosphate (ADP) - as well as in signal transduction as cyclic adenosine monophosphate, cAMP. It is also an inhibitory neurotransmitter, believed to play a role in promoting sleep and suppressing arousal, with levels increasing with each hour an organism is awake. Biochemistry is the study of the chemical processes in living organisms. ... Adenosine 5-triphosphate (ATP) is a multifunctional nucleotide that is most important as a molecular currency of intracellular energy transfer. ... Adenosine diphosphate, abbreviated ADP, is a nucleotide. ... In biology, signal transduction refers to any process by which a cell converts one kind of signal or stimulus into another, most often involving ordered sequences of biochemical reactions inside the cell, that are carried out by enzymes and linked through second messengers resulting in what is thought of as... Structure of cAMP cAMP represented in three ways, the left with sticks-representation, the middle with structure formula, and the right with space filled representation. ...

Contents

Pharmacological effects

Adenosine is an endogenous purine nucleoside that modulates many physiologic processes. Cellular signaling by adenosine occurs through four known adenosine receptor subtypes (A1, A2A, A2B, and A3), all of which are seven transmembrane spanning G-protein coupled receptors. These four receptor subtypes are further classified based on their ability to either stimulate or inhibit adenylate cyclase activity. The A2A and A2B receptors couple to Gάs and mediate the stimulation of adenylate cyclase, while the A1 and A3 adenosine receptors couple to Gάi which inhibits adenylate cyclase activity. Additionally, A1 receptors couple to Gάo, which has been reported to mediate adenosine inhibition of Ca2+ conductance, whereas A2B and A3 receptors also couple to Gάq and stimulate phospholipase activity. Extracellular adenosine concentrations from normal cells are approximately 300 nM; however, in response to cellular damage (e.g. in inflammatory or ischemic tissue), these concentrations are quickly elevated (600-1,200 nM). Thus, in regards to stress or injury, the function of adenosine is primarily that of cytoprotection preventing tissue damage during instances of hypoxia, ischemia, and seizure activity. Activation of A2A receptors produces a constellation of responses that in general can be classified as anti-inflammatory.


Anti-inflammatory Properties

Adenosine is a potent anti-inflammatory agent, acting at its four G-protein coupled receptors. Topical treatment of adenosine to foot wounds in diabetes mellitus has been shown in lab animals to drastically increase tissue repair and reconstruction. Topical administration of adenosine for use in wound healing deficiencies and diabetes mellitus in humans is currently under clinical investigation. For the disease characterized by excretion of large amounts of very dilute urine, see diabetes insipidus. ...


Action on the heart

When administered intravenously, adenosine causes transient heart block in the AV node. This is mediated via the A1 receptor, inhibiting adenyl cyclase, reducing cAMP and so causing cell hyperpolarisation by increasing outward K+ flux. It also causes endothelial dependent relaxation of smooth muscle as is found inside the artery walls. This causes dilatation of the "normal" segments of arteries where the endothelium is not separated from the tunica media by atherosclerotic plaque. This feature allows physicians to use adenosine to test for blockages in the coronary arteries, by exaggerating the difference between the normal and abnormal segments. A heart block is a disease in the electrical system of the heart. ... The atrioventricular node (abbreviated AV node) is the tissue between the atria and the ventricles of the heart, which conducts the normal electrical impulse from the atria to the ventricles. ... The endothelium is the layer of thin, flat cells that lines the interior surface of blood vessels, forming an interface between circulating blood in the lumen and the rest of the vessel wall. ...


In individuals suspected of suffering from a supraventricular tachycardia (SVT), adenosine is used to help identify the rhythm. Certain SVTs can be successfully terminated with adenosine. This includes any re-entrant arrhythmias that require the AV node for the re-entry (e.g., AV reentrant tachycardia (AVRT), AV nodal reentrant tachycardia (AVNRT). In addition, atrial tachycardia can sometimes be terminated with adenosine. A supraventricular tachycardia (SVT) is a rapid rhythm of the heart in which the origin of the electrical signal is either the atria or the AV node. ... This article or section cites very few or no references or sources. ... AV nodal reentrant tachycardia (AVNRT) is a type of reentrant tachycardia (fast rhythm) of the heart. ...


Adenosine has an indirect effect on atrial tissue causing a shortening of the refractory period. When administered via a central lumen catheter, adenosine has been shown to initiate atrial fibrillation because of its effect on atrial tissue. In individuals with accessory pathways, the onset of atrial fibrillation can lead to a life threatening ventricular fibrillation.


Fast rhythms of the heart that are confined to the atria (e.g., atrial fibrillation, atrial flutter) or ventricles (e.g., monomorphic ventricular tachycardia) and do not involve the AV node as part of the re-entrant circuit are not typically converted by adenosine, however the ventricular response rate will be temporarily slowed. In anatomy, the atrium (plural: atria) is the blood collection chamber of a heart. ... Atrial fibrillation (AF or afib) is a cardiac arrhythmia (abnormal heart rhythm) that involves the two upper chambers (atria) of the heart. ... Atrial flutter is an abnormal fast heart rhythm that occurs in the atria of the heart. ... In the heart, a ventricle is a heart chamber which collects blood from an atrium (another heart chamber that is smaller than a ventricle) and pumps it out of the heart. ... Ventricular tachycardia (V-tach or VT) is a tachycardia, or fast heart rhythm that originates in one of the ventricles of the heart. ...


Because of the effects of adenosine on AV node-dependent SVTs, adenosine is considered a class V antiarrhythmic agent. When adenosine is used to cardiovert an abnormal rhythm, it is normal for the heart to enter ventricular asystole for a few seconds. This can be very disconcerting to a normally conscious patient, and is associated with very unpleasant sensations in the chest. Antiarrhythmic agents are a group of pharmaceuticals that are used to suppress fast rhythms of the heart (cardiac arrhythmias), such as atrial fibrillation, atrial flutter, ventricular tachycardia, and ventricular fibrillation. ...

Caffeine's principal mode of action is as an antagonist of adenosine receptors in the brain. They are presented here side by side for comparison.
Caffeine's principal mode of action is as an antagonist of adenosine receptors in the brain. They are presented here side by side for comparison.

The pharmacological effects of adenosine may be blunted in individuals who are taking large quantities of methylxanthines (e.g., caffeine (found in coffee) and theophylline (found predominantly in tea)). Image File history File links Caffeine_and_adenosine. ... Image File history File links Caffeine_and_adenosine. ... Caffeine is a xanthine alkaloid compound that acts as a stimulant in humans. ... Antagonists will block the binding of an agonist at a receptor molecule, inhibiting the signal produced by a receptor-agonist coupling. ... Xanthines are a group of alkaloids that are commonly used for their effects as mild stimulants and as bronchodilators, notably in treating the symptoms of asthma. ... Caffeine is a xanthine alkaloid compound that acts as a stimulant in humans. ... Theophylline is a methylxanthine drug used in therapy for respiratory diseases such as COPD or asthma under a variety of brand names. ...


Caffeine's stimulatory effects are primarily (although not entirely) credited to its inhibition of adenosine by binding to the same receptors. By nature of caffeine's purine structure it binds to some of the same receptors as adenosine, effectively blocking adenosine receptors in the central nervous system. This reduction in adenosine activity leads to increased activity of the neurotransmitters dopamine and glutamate. Purine is a heterocyclic aromatic organic compound, consisting of a pyrimidine ring fused to an imidazole ring. ... Chemical structure of D-aspartic acid, a common amino acid neurotransmitter. ... For other uses, see Dopamine (disambiguation). ... Glutamate is the anion of glutamic acid. ...


Dosage

When given for the evaluation or treatment of an SVT, the initial dose is 6 mg, given as a fast IV/Intraosseous IO push. Due to adenosine's extremely short half-life, the IV line is started as proximal to the heart as possible, such as the antecubital fossa. The IV push is often followed with an immediate flush of 5-10ccs of saline. If this has no effect (e.g., no evidence of transient AV block), a 12mg dose can be given 1-2 minutes after the first dose. If the 12mg dose has no effect, a second 12mg dose can be administered 1-2 minutes after the previous dose. Some clinicians may prefer to administer a higher dose (typically 18 mg), rather than repeat a dose that apparently had no effect. When given to dilate the arteries, such as in a "stress test", the dosage is typically 0.14 mg/kg/min, administered for 4 or 6 minutes, depending on the protocol. An intravenous drip in a hospital Intravenous therapy or IV therapy is the administration of liquid substances directly into a vein. ... Look up Io, io in Wiktionary, the free dictionary. ...


The recommended dose may be increased in patients on theophylline since methylxanthines prevent binding of adenosine at receptor sites. The dose is often decreased in patients on dipyridamole (Persantine) and diazepam (Valium) because adenosine potentiates the effects of these drugs. The recommended dose is also reduced by half in patients who are presenting Congestive Heart Failure, Myocardial Infarction, shock, hypoxia, and/or hepatic or renal insufficiency, and in elderly patients. Congestive heart failure (CHF), also called congestive cardiac failure (CCF) or just heart failure, is a condition that can result from any structural or functional cardiac disorder that impairs the ability of the heart to fill with or pump a sufficient amount of blood throughout the body. ... Acute myocardial infarction (AMI or MI), more commonly known as a heart attack, is a disease state that occurs when the blood supply to a part of the heart is interrupted. ... This article is about the medical condition. ... Hypoxia may refer to: Hypoxia (medical), the lack of oxygen in tissues Hypoxia or Oxygen depletion, a reduced concentration of dissolved oxygen in a water body leading to stress or even death in aquatic organisms This is a disambiguation page: a list of articles associated with the same title. ... Old age consists of ages nearing the average lifespan of human beings, and thus the end of the human life cycle. ...


Drug Interactions

Beta blockers and dopamine may precipitate toxicity in the patient. Beta blockers or beta-adrenergic blocking agents are a class of drugs used to treat a variety of cardiovascular conditions and some other diseases. ...


Contraindications

Poison/Drug induced tachycardia, Asthma (relative contraindication), 2nd or 3rd degree heart block, Atrial fibrillation, atrial flutter, Ventricular tachycardia, Sick sinus syndrome, Stokes-Adams Attack, Wolf-Parkinson-White syndrome, bradycardia with Premature Ventricular Contractions (PVCs). A heart block is a disease in the electrical system of the heart. ... Atrial fibrillation (AF or afib) is a cardiac arrhythmia (abnormal heart rhythm) that involves the two upper chambers (atria) of the heart. ... Atrial flutter is an abnormal fast heart rhythm that occurs in the atria of the heart. ... Ventricular tachycardia (V-tach or VT) is a fast rhythm that originates in one of the ventricles of the heart. ... Sick sinus syndrome, also called Bradycardia-tachycardia syndrome is a group of abnormal heartbeats (arrhythmias) presumably caused by a malfunction of the sinus node, the hearts natural pacemaker. ... The term Stokes-Adams Attack refers to a sudden, transient episode of syncope, occasionally featuring seizures. ... Wolff-Parkinson-White syndrome (WPW) is a syndrome of pre-excitation of the ventricles of the heart due to an accessory pathway known as the Bundle of Kent. ... Bradycardia, as applied to adult medicine, is defined as a resting heart rate of under 60 beats per minute, though it is seldom symptomatic until the rate drops below 50 beat/min. ... This article does not cite any references or sources. ...

  • WPW- adenosine may be administered if equipment for cardioversion is immediately available as a backup.
  • A-flutter W/rvr - when it first presents with SVT

Side effects

Many individuals experience facial flushing, lightheadedness, diaphoresis, or nausea after administration of adenosine. These symptoms are transitory, usually lasting less than one minute. Diaphoresis is excessive sweating commonly associated with shock and other medical emergency conditions. ...


Metabolism

When adenosine enters the circulation, it is broken down by adenosine deaminase, which is present in red cells and the vessel wall. Red Teams or Red Cells are U.S. government parlance for teams or units designed to test the effectiveness of U.S. tactics or personnel. ...


Dipyridamole, an inhibitor of adenosine deaminase, allows adenosine to accumulate in the blood stream. This causes an increase in coronary vasodilatation. Dipyridamole is a drug that inhibits platelet aggregation and causes vasodilation. ... Adenosine deaminase (sometimes known as ADA) is an enzyme in the purine metabolism. ...


See also

To meet Wikipedias quality standards, this article or section may require cleanup. ...

External links


v  d  e
Major families of biochemicals
Peptides | Amino acids | Nucleic acids | Carbohydrates | Lipids | Terpenes | Carotenoids | Tetrapyrroles | Enzyme cofactors | Steroids | Flavonoids | Alkaloids | Polyketides | Glycosides
Analogues of nucleic acids: Types of Nucleic Acids Analogues of nucleic acids:
Nucleobases: Purine (Adenine, Guanine) | Pyrimidine (Uracil, Thymine, Cytosine)
Nucleosides: Adenosine/Deoxyadenosine | Guanosine/Deoxyguanosine | Uridine | Thymidine | Cytidine/Deoxycytidine
Nucleotides: monophosphates (AMP, UMP, GMP, CMP) | diphosphates (ADP, UDP, GDP, CDP) | triphosphates (ATP, UTP, GTP, CTP, GTPgammaS) | cyclic (cAMP, cGMP, cADPR)
Deoxynucleotides: monophosphates (dAMP, TMP, dGMP, dCMP) | diphosphates (dADP, TDP, dGDP, dCDP) | triphosphates (dATP, TTP, dGTP, dCTP)
Ribonucleic acids: RNA | mRNA | piRNA | tRNA | rRNA | ncRNA | gRNA | shRNA | siRNA | snRNA | miRNA | snoRNA
Deoxyribonucleic acids: DNA | mtDNA | cDNA | plasmid | Cosmid | BAC | YAC | HAC
Analogues of nucleic acids: GNA | PNA | TNA | Morpholino | LNA

  Results from FactBites:
 
Atlas of Myocardial Perfusion SPECT: adenosine.html (493 words)
Adenosine also stimulates the A1 purine receptors in the SA and AV node leading to slowing of HR and AV conduction delay.
When the flow in the latter increases during Adenosine infusion and the pressure decrease, flow in the collateral'smay reverse, blood is being "sucked" over fro the stenotic vessel leading to real hypoperfusion and ischemia in the stenotic artery.
Adenosine is the protocol of choice in patient with significant arrhythmia and in patient with psychiatric history.
Adenosine triphosphate - Wikipedia, the free encyclopedia (719 words)
Adenosine 5'-triphosphate (ATP) is the nucleotide known in biochemistry as the "molecular currency" of intracellular energy transfer; that is, ATP is able to store and transport chemical energy within cells.
In signal transduction pathways, ATP is used to provide the phosphate for the protein-kinase reactions.
ATP consists of adenosine and three phosphate groups(triphosphate).
  More results at FactBites »

 
 

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