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Adenosine is an
organic compound , CH4; is among the simplest organic compounds. In chemistry Chemistry is the scientific discipline involved with Chemical element, elements and chemical compound, compounds composed of atoms, molecules and ions: their composition, structure, ...
that occurs widely in nature in the form of diverse derivatives. The molecule consists of an
adenine Adenine (A, Ade) is a nucleobase (a purine Purine is a heterocyclic compound, heterocyclic aromatic organic compound that consists of two rings (pyrimidine and imidazole). It is water-soluble. Purine also gives its name to the wider class of m ...

adenine
attached to a
ribose Ribose is a simple sugar and carbohydrate is a disaccharide found in animal milk. It consists of a molecule of D-galactose and a molecule of D-glucose bonded by beta-1-4 glycosidic linkage. A carbohydrate () is a biomolecule consisting ...

ribose
via a β-N9-
glycosidic bond A glycosidic bond or glycosidic linkage is a type of covalent bond A covalent bond is a chemical bond A chemical bond is a lasting attraction between atoms, ions or molecules that enables the formation of chemical compounds. The bond may ...
. Adenosine is one of four
nucleoside Nucleosides are glycosylamines that can be thought of as nucleotide Nucleotides are organic molecules consisting of a nucleoside and a phosphate. They serve as monomeric units of the nucleic acid polymers deoxyribonucleic acid (DNA) and ribonuc ...

nucleoside
building blocks to
DNA Deoxyribonucleic acid (; DNA) is a molecule File:Pentacene on Ni(111) STM.jpg, A scanning tunneling microscopy image of pentacene molecules, which consist of linear chains of five carbon rings. A molecule is an electrically neutral gro ...

DNA
and
RNA Ribonucleic acid (RNA) is a polymer A polymer (; Greek '' poly-'', "many" + '' -mer'', "part") is a substance or material consisting of very large molecule File:Pentacene on Ni(111) STM.jpg, A scanning tunneling microscopy image of ...

RNA
, which are essential for all life. Its derivatives include the energy carriers
adenosine mono-, di-, and triphosphate
adenosine mono-, di-, and triphosphate
, also known as AMP/ADP/ATP.
Cyclic adenosine monophosphate Cyclic adenosine monophosphate (cAMP, cyclic AMP, or 3',5'-cyclic adenosine monophosphate) is a second messenger important in many biological processes. cAMP is a derivative of adenosine triphosphate (ATP) and used for intracellular signal tran ...
(cAMP) is pervasive in
signal transduction Signal transduction is the process by which a chemical or physical signal is transmitted through a cell as a series of molecular events, most commonly protein phosphorylation residue Protein phosphorylation is a reversible post-translational m ...
. Adenosyl (Ad) is the radical formed by removal of the 5′-hydroxy (OH) group. Ad is found in
vitamin B12 Vitamin B12, also known as cobalamin, is a water-soluble vitamin involved in metabolism. It is one of eight B vitamins. It is required by animals, which use it as a cofactor (biochemistry), cofactor in DNA synthesis, in both fatty acid metabo ...

vitamin B12
and the
radical SAM Radical SAM is a designation for a superfamily of enzymes that use a +_cluster.html" ;"title="Fe-4Ssup>+ cluster">Fe-4Ssup>+ cluster to reductively cleave S-Adenosyl methionine, ''S''-adenosyl-L-methionine (SAM) to generate a radical (chemistry), ...
enzymes. Adenosine is also used as a medication.


Medical uses


Supraventricular tachycardia

In individuals with
supraventricular tachycardia Supraventricular tachycardia (SVT) is an umbrella term for arising from the . This is in contrast to the other group of fast heart rhythms - , which start within the . There are four main types of SVT: , , (PSVT) and . The symptoms of SVT incl ...
(SVT), adenosine is used to help identify and convert the rhythm. Certain SVTs can be successfully terminated with adenosine. This includes any
re-entrant arrhythmia Arrhythmia, also known as cardiac arrhythmia or heart arrhythmia, is a group of conditions in which the Cardiac cycle, heartbeat is irregular, too fast, or too slow. The heart rate that is too fast – above 100 beats per minute in adults – is ...
s that require the AV node for the re-entry, e.g.,
AV reentrant tachycardia Atrioventricular reentrant tachycardia (AVRT), or atrioventricular reciprocating tachycardia, is a type of abnormal fast heart rhythm and is classified as a type of supraventricular tachycardia Supraventricular tachycardia (SVT) is an tachycar ...
(AVRT),
AV nodal reentrant tachycardia AV-nodal reentrant tachycardia (AVNRT) is a type of abnormal fast heart rhythm. It is a type of supraventricular tachycardia (SVT), meaning that it originates from a location within the heart above the bundle of His. AV nodal reentrant tachycar ...

AV nodal reentrant tachycardia
(AVNRT). In addition,
atrial tachycardia Atrial tachycardia is a type of heart rhythm problem in which the heart The heart is a muscle, muscular Organ (anatomy), organ in most animals, which pumps blood through the blood vessels of the circulatory system. The pumped blood carries ...
can sometimes be terminated with adenosine. Fast rhythms of the heart that are confined to the
atriaAtria may refer to: *Atrium (heart) The atrium (Latin ātrium, “entry hall”) is the upper chamber through which blood enters the Ventricle (heart), ventricles of the heart. There are two atria in the human heart – the left atrium receives bloo ...
(e.g.,
atrial fibrillation Atrial fibrillation (AF or A-fib) is an abnormal heart rhythm (arrhythmia) characterized by the rapid and irregular beating of the atrial chambers of the heart. It often begins as short periods of abnormal beating, which become longer or cont ...

atrial fibrillation
,
atrial flutter Atrial flutter (AFL) is a common abnormal heart rhythm that starts in the atrial chambers of the heart The heart is a muscle, muscular Organ (anatomy), organ in most animals, which pumps blood through the blood vessels of the circulatory ...
) or ventricles (e.g.,
monomorphic ventricular tachycardia Ventricular tachycardia (V-tach or VT) is a type of regular, fast heart rate that arises from improper electrical activity in the ventricles of the heart The heart is a muscle, muscular Organ (anatomy), organ in most animals, which pump ...
) 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 is temporarily slowed with adenosine in such cases. Because of the effects of adenosine on AV node-dependent SVTs, adenosine is considered a class V
antiarrhythmic agent Antiarrhythmic agents, also known as cardiac dysrhythmia medications, are a group of pharmaceuticals that are used to suppress abnormal rhythms of the heart (cardiac arrhythmias), such as atrial fibrillation, atrial flutter, ventricular tachycardia ...
. When adenosine is used to
cardiovert
cardiovert
an abnormal rhythm, it is normal for the heart to enter ventricular
asystole Asystole is the absence of ventricular contractions in the context of a lethal heart arrhythmia (in contrast to an induced asystole on a cooled patient on a heart-lung machine and general anesthesia during surgery necessitating stopping the heart). ...

asystole
for a few seconds. This can be disconcerting to a normally conscious patient, and is associated with angina-like sensations in the chest.


Nuclear stress test

Adenosine is used as an adjunct to
thallium Thallium is a chemical element upright=1.0, 500px, The chemical elements ordered by link=Periodic table In chemistry Chemistry is the science, scientific study of the properties and behavior of matter. It is a natural science tha ...

thallium
(TI 201) or technetium (Tc99m)
myocardial perfusion scintigraphy Myocardial perfusion imaging or scanning (also referred to as MPI or MPS) is a nuclear medicine procedure that illustrates the function of the heart muscle (myocardium). It evaluates many heart conditions, such as coronary artery disease (CAD), hy ...
(nuclear stress test) in patients unable to undergo adequate stress testing with exercise.


Dosage

When given for the evaluation or treatment of a
supraventricular tachycardia Supraventricular tachycardia (SVT) is an umbrella term for arising from the . This is in contrast to the other group of fast heart rhythms - , which start within the . There are four main types of SVT: , , (PSVT) and . The symptoms of SVT incl ...
(SVT), the initial dose is 6 mg to 12 mg, depending on standing orders or provider preference, given as a rapid parenteral infusion. Due to adenosine's extremely short half-life, the IV line is started as proximal (near) to the heart as possible, such as the
antecubital fossa The cubital fossa, chelidon, or elbow pit is the triangular area on the anterior side of the upper limb between the arm and forearm of a human or other hominid animals. It lies anterior Standard anatomical terms of location deal unambiguously with ...
. The IV push is often followed with a flush of 10–20 mL of normal saline. If this has no effect (i.e., no evidence of transient AV block), a dose of 12 mg can be given 1–2 minutes after the first dose. 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. 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 Dipyridamole (trademarked as Persantine and others) is a nucleoside transport inhibitor and a PDE3 inhibitor medication that inhibits thrombus, blood clot formation when given chronically and causes vasodilation, blood vessel dilation when given ...

dipyridamole
(Persantine) and
diazepam Diazepam, first marketed as Valium, is a medicine of the benzodiazepine Benzodiazepines (BZD, BDZ, BZs), sometimes called "benzos", are a class of psychoactive drugs whose core chemical structure is the fusion of a benzene ring and a diazepin ...

diazepam
(Valium) because adenosine potentiates the effects of these drugs. The recommended dose is also reduced by half in patients presenting
congestive heart failure Heart failure (HF), also known as congestive heart failure (CHF) and (congestive) cardiac failure (CCF), is a set of manifestations caused by the failure of the heart The heart is a cardiac muscle, muscular Organ (biology), organ in mos ...
,
myocardial infarction A myocardial infarction (MI), commonly known as a heart attack, occurs when blood flow Hemodynamics American and British English spelling differences#ae and oe, or haemodynamics are the Fluid dynamics, dynamics of blood flow. The circulatory sy ...

myocardial infarction
, shock, hypoxia, and/or chronic liver disease or
chronic kidney disease Chronic kidney disease (CKD) is a type of kidney disease Kidney disease, or renal disease, technically referred to as nephropathy, is damage to or disease A disease is a particular abnormal condition that negatively affects the str ...
, and in
elderly Old age refers to ages nearing or surpassing the life expectancy Life expectancy is a statistical measure of the average time an organism is expected to live, based on the year of its birth, its current age, and other demographic ...
patients.


Drug interactions

Dipyridamole Dipyridamole (trademarked as Persantine and others) is a nucleoside transport inhibitor and a PDE3 inhibitor medication that inhibits thrombus, blood clot formation when given chronically and causes vasodilation, blood vessel dilation when given ...

Dipyridamole
potentiates the action of adenosine, requiring the use of lower doses. 350px,
antagonist An antagonist is a character in a story who is presented as the chief foe of the protagonist 200px, William Shakespeare, Shakespeare's ''Hamlet, Prince of Denmark.'' William Morris Hunt, oil on canvas, c. 1864 A protagonist (from grc, πρω ...
of adenosine receptors in the brain. Methylxanthines (e.g. caffeine found in coffee, theophylline found in tea, or theobromine found in chocolate) have a purine structure and bind to some of the same receptors as adenosine. Methylxanthines act as competitive antagonists of adenosine and can blunt its pharmacological effects. Individuals taking large quantities of methylxanthines may require increased doses of adenosine.


Contraindications

Common
contraindication In medicine Medicine is the science Science () is a systematic enterprise that builds and organizes knowledge Knowledge is a familiarity, awareness, or understanding of someone or something, such as facts ( descriptive knowledge), sk ...
s for adenosine include *
Asthma Asthma is a long-term Long-Term Capital Management L.P. (LTCM) was a hedge fund''A financial History of the United States Volume II: 1970–2001'', Jerry W. Markham, Chapter 5: "Bank Consolidation", M. E. Sharpe, Inc., 2002 based in Greenwich, ...

Asthma
, traditionally considered an absolute
contraindication In medicine Medicine is the science Science () is a systematic enterprise that builds and organizes knowledge Knowledge is a familiarity, awareness, or understanding of someone or something, such as facts ( descriptive knowledge), sk ...
. This is being contended and it is now considered a relative contraindication (however, selective adenosine antagonists are being investigated for use in treatment of asthma)


Side effects


Pharmacological effects

Adenosine is an endogenous purine nucleoside that modulates many physiological processes. Cellular signaling by adenosine occurs through four known adenosine receptor subtypes ( A1, A2A, A2B, and A3). Extracellular adenosine concentrations from normal cells are approximately 300 nM; however, in response to cellular damage (e.g., in inflammatory or
ischemic Ischemia or ischaemia is a restriction in blood Blood is a body fluid Body fluids, bodily fluids, or biofluids are liquid A liquid is a nearly incompressible In fluid mechanics or more generally continuum mechanics, incompressi ...
tissue), these concentrations are quickly elevated (600–1,200 nM). Thus, in regard to stress or injury, the function of adenosine is primarily that of cytoprotection preventing tissue damage during instances of hypoxia,
ischemia Ischemia or ischaemia is a restriction in blood Blood is a body fluid Body fluids, bodily fluids, or biofluids are liquid A liquid is a nearly incompressible fluid In physics, a fluid is a substance that continually Deformation ( ...
, and seizure activity. Activation of A2A receptors produces a constellation of responses that in general can be classified as anti-inflammatory. Enzymatic production of adenosine can be anti-
inflammatory Inflammatory may refer to: * Inflammation, a biological response to harmful stimuli * The word ''inflammatory'' is also used to refer literally to fire and flammability, and figuratively in relation to comments that are Agent provocateur, provocati ...
or
immunosuppressive Immunosuppression is a reduction of the activation or efficacy Efficacy is the ability to perform a task to a satisfactory or expected degree. The word comes from the same roots as '' effectiveness'', and it has often been used synonymously, alt ...
.


Adenosine receptors

All adenosine receptor subtypes (A1, A2A, A2B, and A3) are
G-protein-coupled receptors G protein-coupled receptors (GPCRs), also known as seven-(pass)-transmembrane domain receptors, 7TM receptors, heptahelical receptors, serpentine receptors, and G protein-linked receptors (GPLR), form a large group of protein family, evolutionari ...
. The four receptor subtypes are further classified based on their ability to either stimulate or inhibit
adenylate cyclase
adenylate cyclase
activity. The A1 receptors couple to Gi/o and decreases cAMP levels, while the A2 adenosine receptors couple to Gs, which stimulates adenylate cyclase activity. In addition, A1 receptors couple to Go, which has been reported to mediate adenosine inhibition of Ca2+ conductance, whereas A2B and A3 receptors also couple to Gq and stimulate
phospholipase A phospholipase is an enzyme that hydrolyzes phospholipid Phospholipids, also known as phosphatides, are a class of lipid In and , a lipid is a macro that is soluble in solvents. are typically s used to dissolve other naturally occurr ...

phospholipase
activity. Researchers at Cornell University have recently shown adenosine receptors to be key in opening the blood-brain barrier (BBB). Mice dosed with adenosine have shown increased transport across the BBB of amyloid plaque antibodies and prodrugs associated with Parkinson's disease, Alzheimer's, multiple sclerosis, and cancers of the central nervous system.


Ghrelin/growth hormone secretagogue receptor

Adenosine is an
endogenous Endogenous substances and processes are those that originate from within a system such as an organism In biology Biology is the natural science that studies life and living organisms, including their anatomy, physical structure, Bi ...
agonist An agonist is a chemical that binds to a receptor and activates the receptor to produce a biological response. In contrast, an antagonist blocks the action of the agonist, while an inverse agonist causes an action opposite to that of the agonist ...

agonist
of the ghrelin/growth hormone secretagogue receptor. However, while it is able to increase
appetite Appetite is the desire to eat Eating (also known as consuming) is the ingestion of food Food is any substance consumed to provide nutritional support for an organism In biology, an organism (from Ancient Greek, Greek: ὀργα ...
, unlike other agonists of this receptor, adenosine is unable to induce the secretion of
growth hormone Growth hormone (GH) or somatotropin, also known as human growth hormone (hGH or HGH) in its human form, is a peptide hormone that stimulates growth, cell (biology), cell reproduction, and cell regeneration in humans and other animals. It is th ...
and increase its plasma levels.


Mechanism of action

When it is administered intravenously, adenosine causes transient
heart block Heart block (HB) is a disorder in the heart The heart is a muscle, muscular Organ (anatomy), organ in most animals, which pumps blood through the blood vessels of the circulatory system. The pumped blood carries oxygen and nutrients to the ...

heart block
in the atrioventricular (AV) node. This is mediated via the A1 receptor, inhibiting adenylyl cyclase, reducing cAMP and so causing cell hyperpolarization by increasing K+ efflux via , subsequently inhibiting Ca2+ current. It also causes endothelial-dependent relaxation of smooth muscle as is found inside the artery walls. This causes dilation of the "normal" segments of arteries, i.e. where the
endothelium Endothelium is a single layer of squamous Epithelium () is one of the four basic types of animal Animals (also called Metazoa) are multicellular eukaryotic organisms that form the Kingdom (biology), biological kingdom Animalia. Wit ...
is not separated from the tunica media by
atherosclerotic plaque An atheroma, or atheromatous plaque ("plaque"), is an abnormal accumulation of material in the inner layer of the wall of an artery An artery (plural arteries) () is a blood vessel that takes blood away from the heart to one or more parts of ...
. 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. The administration of adenosine also reduces blood flow to coronary arteries past the occlusion. Other coronary arteries dilate when adenosine is administered while the segment past the occlusion is already maximally dilated, which is a process called coronary steal. This leads to less blood reaching the ischemic tissue, which in turn produces the characteristic chest pain.


Metabolism

Adenosine used as a
second messenger Second messengers are intracellular signaling molecules released by the cell in response to exposure to extracellular signaling molecules—the first messengers. (Intracellular signals, a non-local form or cell signaling In biology Biology is ...
can be the result of ''de novo'' via
adenosine monophosphate Adenosine is an organic compound In chemistry Chemistry is the study of the properties and behavior of . It is a that covers the that make up matter to the composed of s, s and s: their composition, structure, properties, behavior ...
(AMP), though it is possible other pathways exist. When adenosine enters the circulation, it is broken down by
adenosine deaminase Adenosine deaminase (also known as adenosine aminohydrolase, or ADA) is an enzyme Enzymes () are proteins that act as biological catalysts (biocatalysts). Catalysts accelerate chemical reactions. The molecules upon which enzymes may act are ...
, which is present in
red blood cell Red blood cells (RBCs), also referred to as red cells, red blood corpuscles (in humans or other animals not having nucleus in red blood cells), haematids, erythroid cells or erythrocytes (from Greek language, Greek ''erythros'' for "red" and ''k ...

red blood cell
s and the vessel wall.
Dipyridamole Dipyridamole (trademarked as Persantine and others) is a nucleoside transport inhibitor and a PDE3 inhibitor medication that inhibits thrombus, blood clot formation when given chronically and causes vasodilation, blood vessel dilation when given ...

Dipyridamole
, an inhibitor of adenosine nucleoside transporter, allows adenosine to accumulate in the blood stream. This causes an increase in coronary vasodilatation.
Adenosine deaminase deficiency Adenosine deaminase deficiency (ADA deficiency) is a metabolic disorder A metabolic disorder is a disorder that negatively alters the body's processing and distribution of macronutrients such as proteins, fats, and carbohydrates. Metabolic dis ...
is a known cause of immunodeficiency.


Research


Viruses

The adenosine analog has been reported to directly inhibit the recombinant RNA-dependent
RNA polymerase In molecular biology Molecular biology is the branch of biology that seeks to understand the molecule, molecular basis of biological activity in and between Cell (biology), cells, including biomolecule, molecular synthesis, modification, m ...

RNA polymerase
of the
dengue virus ''Dengue virus'' (DENV) is the cause of dengue fever Dengue fever is a mosquito-borne tropical disease Tropical diseases are Infectious disease, diseases that are prevalent in or unique to tropics, tropical and subtropics, subtropical regi ...
by terminating its RNA chain synthesis. This interaction suppresses peak
viremia Viremia is a medical condition where virus A virus is a submicroscopic infectious agent that Viral replication, replicates only inside the living Cell (biology), cells of an organism. Viruses infect all types of life forms, from animals a ...
and rise in
cytokine Cytokines are a broad and loose category of small protein Proteins are large biomolecule , showing alpha helices, represented by ribbons. This poten was the first to have its suckture solved by X-ray crystallography by Max Perutz and ...

cytokine
s and prevents lethality in infected animals, raising the possibility of a new treatment for this
flavivirus , subdivision = #Taxonomy, See text ''Flavivirus'' is a genus of positive-strand RNA viruses in the family ''Flaviviridae''. The genus includes the West Nile virus, dengue virus, dengue virus, tick-borne encephalitis virus, yellow fever virus, ...
. The 7-deaza-adenosine analog has been shown to inhibit the replication of the
hepatitis C virus The hepatitis C virus (HCV) is a small (55–65 nm in size), enveloped, positive-sense single-stranded RNA virus An RNA virus is a virus A virus is a submicroscopic infectious agent that Viral replication, replicates only inside ...
. is protective against
Ebola Ebola, also known as Ebola virus disease (EVD) and Ebola hemorrhagic fever (EHF), is a viral hemorrhagic fever Viral hemorrhagic fevers (VHFs) are a diverse group of animal and human illness A disease is a particular abnormal c ...
and
Marburg Marburg ( or ) is a college town, university town in the States of Germany, German federal state (''Bundesland'') of Hesse, capital of the Marburg-Biedenkopf Districts of Germany, district (''Landkreis''). The town area spreads along the valley ...
viruses. Such adenosine analogs are potentially clinically useful since they can be taken orally.


Anti-inflammatory properties

Adenosine is believed to be an
anti-inflammatoryAnti-inflammatory (or antiinflammatory) is the property of a substance or treatment that reduces inflammation or swelling. Anti-inflammatory drugs make up about half of analgesics, remedying pain by reducing inflammation as opposed to opioids, whic ...
agent at the A2A receptor. Topical treatment of adenosine to foot wounds in
diabetes mellitus Diabetes mellitus, commonly known as just diabetes, is a group of metabolic disorders characterized by a hyperglycemia, high blood sugar level over a prolonged period of time. Symptoms often include frequent urination, Polydipsia, increased th ...
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.
Methotrexate Methotrexate (MTX), formerly known as amethopterin, is a chemotherapy agent and immunosuppressive drug, immune-system suppressant. It is used to treat cancer, autoimmune diseases, and ectopic pregnancy and for medical abortions. Types of cancers ...

Methotrexate
's anti-inflammatory effect may be due to its stimulation of adenosine release.


Central nervous system

In general, adenosine has an inhibitory effect in the
central nervous system The central nervous system (CNS) is the part of the nervous system In biology Biology is the natural science that studies life and living organisms, including their anatomy, physical structure, Biochemistry, chemical processes, Molecu ...

central nervous system
(CNS).
Caffeine Caffeine is a central nervous system The central nervous system (CNS) is the part of the nervous system In biology Biology is the natural science that studies life and living organisms, including their anatomy, physical structu ...

Caffeine
's stimulatory effects are credited primarily (although not entirely) to its capacity to block adenosine receptors, thereby reducing the inhibitory tonus of adenosine in the CNS. This reduction in adenosine activity leads to increased activity of the
neurotransmitter A neurotransmitter is a signaling molecule In biology, cell signaling (cell signalling in British English), or cell-cell communication, governs the basic activities of cells and coordinates multiple-cell actions. A signal is an entity that ...
s
dopamine Dopamine (DA, a contraction of 3,4-dihydroxyphenethylamine) is a neuromodulatory molecule that plays several important roles in cells. It is an organic chemical , CH4; is among the simplest organic compounds. In chemistry Chemistry is t ...

dopamine
and
glutamate Glutamic acid (symbol Glu or E; the ionic form is known as glutamate) is an α-amino acid Amino acids are organic compounds that contain amino (–NH2) and Carboxylic acid, carboxyl (–COOH) functional groups, along with a Substituent, sid ...
. Experimental evidence suggests that adenosine and adenosine agonists can activate
Trk receptor Trk receptors are a family of receptor tyrosine kinase, tyrosine kinases that regulates Chemical synapse, synaptic strength and Synaptic plasticity, plasticity in the mammalian nervous system. Trk receptors affect neuronal survival and Cellular dif ...
phosphorylation through a mechanism that requires the adenosine A2A receptor.


Hair

Adenosine has been shown to promote thickening of hair on people with thinning hair. A 2013 study compared topical adenosine with
minoxidil Minoxidil (2,4-diamino-6-piperidinopyrimidine 3-oxide), sold under the brand name Rogaine among others, is a medication used for the treatment of Hypertension, high blood pressure and male-pattern hair loss, pattern hair loss in males and females ...

minoxidil
in male androgenetic alopecia, finding it was as potent as minoxidil (in overall treatment outcomes) but with higher satisfaction rate with patients due to “faster prevention of hair loss and appearance of the newly grown hairs” (further trials were called for to clarify the findings).


Sleep

The principal component of
cannabis ''Cannabis'' () is a genus Genus /ˈdʒiː.nəs/ (plural genera /ˈdʒen.ər.ə/) is a taxonomic rank In biological classification In biology Biology is the natural science that studies life and living organisms, including ...
delta-9-tetrahydrocannabinol Tetrahydrocannabinol (THC) is one of at least 113 cannabinoids identified in cannabis (drug), cannabis. THC is the principal psychoactive drug, psychoactive constituent of cannabis. Although the chemical formula for THC (C21H30O2) describes multi ...

delta-9-tetrahydrocannabinol
(THC) and the
endocannabinoid Cannabinoids () are compounds found in cannabis. The most notable cannabinoid is the phytocannabinoid tetrahydrocannabinol (THC) (Delta9-THC or Delta8-THC), the primary psychoactive drug, psychoactive compound in cannabis. Cannabidiol (CBD) is anot ...
anandamide Anandamide (ANA), also known as ''N''-arachidonoylethanolamine (AEA), is a fatty acid neurotransmitter Neurotransmitters are chemical messengers that transmit a signal from a neuron across the synapse to a target cell, which can be a differe ...

anandamide
(AEA) induce
sleep Sleep is a naturally recurring state of mind and body, characterized by altered consciousness Consciousness, at its simplest, is or of internal and external existence. Despite millennia of analyses, definitions, explanations and deba ...

sleep
in
rat Rats are various medium-sized, long-tailed rodent Rodents (from Latin Latin (, or , ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken in the area a ...

rat
s by increasing adenosine levels in the
basal forebrain The basal forebrain structures are located in the forebrain to the front of and below the striatum. They include the ventral basal ganglia (including nucleus accumbens and ventral pallidum), nucleus basalis, diagonal band of Broca, substantia ...

basal forebrain
. They also significantly increase
slow-wave sleep Slow-wave sleep (SWS), often referred to as deep sleep, consists of stage three of non-rapid eye movement sleep. Initially, SWS consisted of both Stage 3, which has 20–50 percent delta wave, delta wave activity, and Stage 4, which has more tha ...
during the third hour, mediated by
CB1 receptor Cannabinoid receptor type 1 (CB1), also known as cannabinoid receptor 1, is a G protein-coupled receptor, G protein-coupled cannabinoid receptor that in humans is encoded by the ''CNR1'' gene. The human CB1 receptor is gene expression, expressed in ...
activation Activation, in chemistry and biology, is the process A process is a series or set of activities that interact to produce a result; it may occur once-only or be recurrent or periodic. Things called a process include: Business and management *B ...
. These findings identify a potential of
cannabinoid Cannabinoids () are compounds found in Cannabis (drug), cannabis. The most notable cannabinoid is the phytocannabinoid tetrahydrocannabinol (THC) (Delta9-THC or Delta8-THC), the primary psychoactive drug, psychoactive compound in cannabis. Cannabid ...
s to induce sleep in conditions where sleep may be severely attenuated.


Vasodilation

It also plays a role in regulation of blood flow to various organs through
vasodilation Vasodilation is the widening of blood vessel The blood vessels are the components of the circulatory system The circulatory system, also called the cardiovascular system or the vascular system, is an organ system An organ system is ...

vasodilation
.


See also

*
Adenosine receptor The adenosine receptors (or P1 receptors) are a class of purinergic G protein-coupled receptor G protein-coupled receptors (GPCRs), also known as seven-(pass)-transmembrane domain receptors, 7TM receptors, heptahelical receptors, serpentine re ...
*
Adenosine reuptake inhibitor An adenosine reuptake inhibitor (AdoRI) is a type of drug A drug is any chemical substance that causes a change in an organism's physiology or psychology when consumed. Drugs are typically distinguished from food and substances that provide ...
* List of growth hormone secretagogues


References

{{Authority control Adenosine receptor agonists Antiarrhythmic agents Chemical substances for emergency medicine Drugs acting on the cardiovascular system Ghrelin receptor agonists Nucleosides Purines Vasodilators Hydroxymethyl compounds