Receptor, Adenosine A2A
Receptor, Adenosine A1
Receptor, Adenosine A3
Receptor, Adenosine A2B
Receptors, Adenosine A2
Adenosine A2 Receptor Agonists
Adenosine A2 Receptor Antagonists
Receptors, Purinergic P1
Adenosine A1 Receptor Antagonists
Purinergic P1 Receptor Antagonists
Adenosine A3 Receptor Antagonists
Dose-Response Relationship, Drug
Nucleoside Transport Proteins
Receptors, Purinergic P2
8-Bromo Cyclic Adenosine Monophosphate
Equilibrative Nucleoside Transporter 1
Adenosine Diphosphate Sugars
Purinergic P2 Receptor Antagonists
Rats, Inbred Strains
Equilibrative-Nucleoside Transporter 2
Cyclic AMP-Dependent Protein Kinases
Ischemic Preconditioning, Myocardial
Analysis of a ubiquitous promoter element in a primitive eukaryote: early evolution of the initiator element. (1/6258)Typical metazoan core promoter elements, such as TATA boxes and Inr motifs, have yet to be identified in early-evolving eukaryotes, underscoring the extensive divergence of these organisms. Towards the identification of core promoters in protists, we have studied transcription of protein-encoding genes in one of the earliest-diverging lineages of Eukaryota, that represented by the parasitic protist Trichomonas vaginalis. A highly conserved element, comprised of a motif similar to a metazoan initiator (Inr) element, surrounds the start site of transcription in all examined T. vaginalis genes. In contrast, a metazoan-like TATA element appears to be absent in trichomonad promoters. We demonstrate that the conserved motif found in T. vaginalis protein-encoding genes is an Inr promoter element. This trichomonad Inr is essential for transcription, responsible for accurate start site selection, and interchangeable between genes, demonstrating its role as a core promoter element. The sequence requirements of the trichomonad Inr are similar to metazoan Inrs and can be replaced by a mammalian Inr. These studies show that the Inr is a ubiquitous, core promoter element for protein-encoding genes in an early-evolving eukaryote. Functional and structural similarities between this protist Inr and the metazoan Inr strongly indicate that the Inr promoter element evolved early in eukaryotic evolution. (+info)
Expression of both P1 and P2 purine receptor genes by human articular chondrocytes and profile of ligand-mediated prostaglandin E2 release. (2/6258)OBJECTIVE: To assess the expression and function of purine receptors in articular chondrocytes. METHODS: Reverse transcriptase-polymerase chain reaction (RT-PCR) was used to screen human chondrocyte RNA for expression of P1 and P2 purine receptor subtypes. Purine-stimulated prostaglandin E2 (PGE2) release from chondrocytes, untreated or treated with recombinant human interleukin-1alpha (rHuIL-1alpha), was assessed by radioimmunoassay. RESULTS: RT-PCR demonstrated that human articular chondrocytes transcribe messenger RNA for the P1 receptor subtypes A2a and A2b and the P2 receptor subtype P2Y2, but not for the P1 receptor subtypes A1 and A3. The P1 receptor agonists adenosine and 5'-N-ethylcarboxamidoadenosine did not change PGE2 release from chondrocytes. The P2Y2 agonists ATP and UTP stimulated a small release of PGE2 that was potentiated after pretreatment with rHuIL-1alpha. PGE2 release in response to ATP and UTP cotreatment was not additive, but release in response to coaddition of ATP and bradykinin (BK) or UTP and BK was additive, consistent with ATP and UTP competition for the same receptor site. The potentiation of PGE2 release in response to ATP and UTP after rHuIL-1alpha pretreatment was mimicked by phorbol myristate acetate. CONCLUSION: Human chondrocytes express both P1 and P2 purine receptor subtypes. The function of the P1 receptor subtype is not yet known, but stimulation of the P2Y2 receptor increases IL-1-mediated PGE2 release. (+info)
Presynaptic action of adenosine on a 4-aminopyridine-sensitive current in the rat carotid body. (3/6258)1. Plasma adenosine concentration increases during hypoxia to a level that excites carotid body chemoreceptors by an undetermined mechanism. We have examined this further by determining the electrophysiological responses to exogenous adenosine of sinus nerve chemoafferents in vitro and of whole-cell currents in isolated type I cells. 2. Steady-state, single-fibre chemoafferent discharge was increased approximately 5-fold above basal levels by 100 microM adenosine. This adenosine-stimulated discharge was reversibly and increasingly reduced by methoxyverapamil (D600, 100 microM), by application of nickel chloride (Ni2+, 2 mM) and by removal of extracellular Ca2+. These effects strongly suggest a presynaptic, excitatory action of adenosine on type I cells of the carotid body. 3. Adenosine decreased whole-cell outward currents at membrane potentials above -40 mV in isolated type I cells recorded during superfusion with bicarbonate-buffered saline solution at 34-36 C. This effect was reversible and concentration dependent with a maximal effect at 10 microM. 4. The degree of current inhibition induced by 10 microM adenosine was voltage independent (45.39 +/- 2. 55 % (mean +/- s.e.m.) between -40 and +30 mV) and largely ( approximately 75 %), but not entirely, Ca2+ independent. 4-Aminopyridine (4-AP, 5 mM) decreased the amplitude of the control outward current by 80.60 +/- 3.67 % and abolished the effect of adenosine. 5. Adenosine was without effect upon currents near the resting membrane potential of approximately -55 mV and did not induce depolarization in current-clamp experiments. 6. We conclude that adenosine acts to inhibit a 4-AP-sensitive current in isolated type I cells of the rat carotid body and suggest that this mechanism contributes to the chemoexcitatory effect of adenosine in the whole carotid body. (+info)
A comparison of an A1 adenosine receptor agonist (CVT-510) with diltiazem for slowing of AV nodal conduction in guinea-pig. (4/6258)1. The purpose of this study was to compare the pharmacological properties (i.e. the AV nodal depressant, vasodilator, and inotropic effects) of two AV nodal blocking agents belonging to different drug classes; a novel A1 adenosine receptor (A1 receptor) agonist, N-(3(R)-tetrahydrofuranyl)-6-aminopurine riboside (CVT-510), and the prototypical calcium channel blocker diltiazem. 2. In the atrial-paced isolated heart, CVT-510 was approximately 5 fold more potent to prolong the stimulus-to-His bundle (S-H interval), a measure of slowing AV nodal conduction (EC50 = 41 nM) than to increase coronary conductance (EC50 = 200 nM). At concentrations of CVT-510 (40 nM) and diltiazem (1 microM) that caused equal prolongation of S-H interval (approximately 10 ms), diltiazem, but not CVT-510, significantly reduced left ventricular developed pressure (LVP) and markedly increased coronary conductance. CVT-510 shortened atrial (EC50 = 73 nM) but not the ventricular monophasic action potentials (MAP). 3. In atrial-paced anaesthetized guinea-pigs, intravenous infusions of CVT-510 and diltiazem caused nearly equal prolongations of P-R interval. However, diltiazem, but not CVT-510, significantly reduced mean arterial blood pressure. 4. Both CVT-510 and diltiazem prolonged S-H interval, i.e., slowed AV nodal conduction. However, the A1 receptor-selective agonist CVT-510 did so without causing the negative inotropic, vasodilator, and hypotensive effects associated with diltiazem. Because CVT-510 did not affect the ventricular action potential, it is unlikely that this agonist will have a proarrythmic action in ventricular myocardium. (+info)
A new synthesis of 5'-deoxy-8,5'-cyclo-adenosine and -inosine: conformationally-fixed purine nucleosides (nucleosides and nucleotides. XVI). (5/6258)A versatile method for the synthesis of 5'-deoxy-8,5'-cycloadenosine, a conformationally-fixed "anti" type of adenosine, was presented. Irradiation of 2', 3'-O-isopropylidene-5'-deoxy-5'-phenylthioadenosine with 60W Hg vapor lamp afforded 2',3'-O-isopropylidene-5'-deoxy-8,5'-cycloadenosine in high yield. The use of other 5'-alkylthio derivatives also gave the cycloadenosine, though the yields were rather poor. Deacetonation of the cyclocompound with 0.1N HCl gave 5'-deoxy-8,5'-cycloadenosine. The cycloinosine derivative was similarly prepared. The nmr, mass and CD spectra of 5'-deoxy-8,5'-cycloadenosine were given and discussed with the previously reported results. (+info)
End group of naturally terminated and UV lesion terminated T7 in vitro RNA. (6/6258)The 3' terminal nucleosides of RNA transcribed in vitro by E. coli RNA polymerase from T7 DNA and UV irradiated TN DNA were determined. The 3' terminal nucleoside of naturally terminated (t1 termination site) RNA cytidine. In the case of RNA terminated at UV lesions, it is cytidine in 0 per cent of the molecules and adenosine in the remaining 30 per cent. Cytidine trialcohols are labile in high concentrations of KOH and at high temperature and appear to convert to uridine. (+info)
Nucleoside-3'-phosphotriesters as key intermediates for the oligoribonucleotide synthesis. III. An improved preparation of nucleoside 3'-phosphotriesters, their 1H NMR characterization and new conditions for removal of 2-cyanoethyl group. (7/6258)An improved procedure for the transformation of 5'-O-monomethoxytrityl-2'-O-acetyl-3'-phosphates of uridine la, inosine ib and 6-N-benzoyladenosine lc into corresponding 3'/2,2,2-trichloroethyl, 2-cyanoethyl/-phosphates iiaic is reported. H NMR characterization of nucleoside 3'-phosphotriesters is presented. New conditions i.e. anhydrous triethylamine-pyridine treatment have been found for the selective removal of 2-cyanoethyl group from nucleoside 3'-phosphotriesters in the presence of neighbouring 2'-O-acetyl one. (+info)
Electrophysiologic effects of adenosine in patients with supraventricular tachycardia. (8/6258)BACKGROUND: We correlated the electrophysiologic (EP) effects of adenosine with tachycardia mechanisms in patients with supraventricular tachycardias (SVT). METHODS AND RESULTS: Adenosine was administered to 229 patients with SVTs during EP study: atrioventricular (AV) reentry (AVRT; n=59), typical atrioventricular node reentry (AVNRT; n=82), atypical AVNRT (n=13), permanent junctional reciprocating tachycardia (PJRT; n=12), atrial tachycardia (AT; n=53), and inappropriate sinus tachycardia (IST; n=10). There was no difference in incidence of tachycardia termination at the AV node in AVRT (85%) versus AVNRT (86%) after adenosine, but patients with AVRT showed increases in the ventriculoatrial (VA) intervals (13%) compared with typical AVNRT (0%), P<0.005. Changes in atrial, AV, or VA intervals after adenosine did not predict the mode of termination of long R-P tachycardias. For patients with AT, there was no correlation with location of the atrial focus and adenosine response. AV block after adenosine was only observed in AT patients (27%) or IST (30%). Patients with IST showed atrial cycle length increases after adenosine (P<0.05) with little change in activation sequence. The incidence of atrial fibrillation after adenosine was higher for those with AVRT (15%) compared with typical AVNRT (0%) P<0.001, or atypical AVNRT (0%) but similar to those with AT (11%) and PJRT (17%). CONCLUSIONS: The EP response to adenosine proved of limited value to identify the location of AT or SVT mechanisms. Features favoring AT were the presence of AV block or marked shortening of atrial cycle length before tachycardia suppression. Atrial fibrillation was more common after adenosine in patients with AVRT, PJRT, or AT. Patients with IST showed increases in cycle length with little change in atrial activation sequence after adenosine. (+info)
Adenosine is a naturally occurring nucleoside that plays a crucial role in various physiological processes in the human body. It is a component of the nucleic acids DNA and RNA and is also found in high concentrations in the cells of the heart, brain, and other organs. In the medical field, adenosine is often used as a medication to treat certain heart conditions, such as supraventricular tachycardia (SVT) and atrial fibrillation (AFib). Adenosine works by blocking the electrical signals that cause the heart to beat too fast or irregularly. It is typically administered as an intravenous injection and has a short duration of action, lasting only a few minutes. Adenosine is also used in research to study the function of various cells and tissues in the body, including the nervous system, immune system, and cardiovascular system. It has been shown to have a wide range of effects on cellular signaling pathways, including the regulation of gene expression, cell proliferation, and apoptosis (cell death).
The Adenosine A2A receptor is a type of protein receptor found on the surface of cells in the body. It is a member of the adenosine receptor family, which is a group of receptors that bind to adenosine, a naturally occurring molecule in the body. The Adenosine A2A receptor plays a role in a variety of physiological processes, including regulating blood flow, modulating the immune system, and influencing mood and behavior. It is also a target for drugs used to treat a range of conditions, including Parkinson's disease, schizophrenia, and depression.
The Adenosine A1 receptor is a type of protein found on the surface of certain cells in the body, including neurons, that binds to the neurotransmitter adenosine. Adenosine is a naturally occurring molecule that helps regulate various physiological processes, such as sleep, heart rate, and blood pressure. When adenosine binds to the A1 receptor, it can trigger a variety of cellular responses, including reducing the activity of neurons, decreasing blood flow to certain tissues, and promoting sleep. The A1 receptor is also involved in the regulation of pain perception, inflammation, and mood. In the medical field, the A1 receptor is an important target for the development of drugs to treat a variety of conditions, including insomnia, anxiety, depression, and Parkinson's disease. Some drugs that target the A1 receptor are already available, while others are still in the development stage.
Adenosine deaminase (ADA) is an enzyme that plays a crucial role in the metabolism of purines, which are nitrogen-containing compounds found in DNA, RNA, and ATP (adenosine triphosphate), the energy currency of cells. In the medical field, ADA deficiency is a rare genetic disorder that affects the immune system and causes a type of combined immunodeficiency disease. People with ADA deficiency have a reduced ability to produce ADA, which leads to an accumulation of toxic levels of adenosine and its metabolites in their cells and tissues. This can cause damage to various organs, including the liver, spleen, and bone marrow, and can lead to recurrent infections, autoimmune disorders, and other complications. ADA deficiency is typically diagnosed through blood tests that measure the levels of ADA activity in the blood and the presence of adenosine and its metabolites in the urine. Treatment for ADA deficiency typically involves enzyme replacement therapy, which involves regular infusions of ADA to replace the missing enzyme and reduce the accumulation of toxic substances in the body.
Adenosine A3 receptor (A3AR) is a type of protein receptor found on the surface of cells in the human body. It is a member of the adenosine receptor family, which is a group of receptors that bind to adenosine, a naturally occurring molecule in the body. The A3AR is primarily expressed in immune cells, such as macrophages and dendritic cells, as well as in certain types of neurons and smooth muscle cells. It plays a role in regulating inflammation, immune responses, and neurotransmission. Activation of the A3AR has been shown to have anti-inflammatory effects, reducing the production of pro-inflammatory cytokines and chemokines. It has also been implicated in the regulation of pain, anxiety, and depression. In the medical field, the A3AR is being studied as a potential target for the development of new drugs for the treatment of a variety of conditions, including inflammatory diseases, cancer, and neurological disorders.
The Adenosine A2B receptor is a type of protein receptor found on the surface of cells in the body. It is a member of the adenosine receptor family, which is a group of receptors that bind to the neurotransmitter adenosine. The Adenosine A2B receptor is activated by the binding of adenosine to its extracellular domain, which triggers a cascade of intracellular signaling events that can affect a variety of cellular processes, including inflammation, cell proliferation, and blood flow. The Adenosine A2B receptor is expressed in a number of different tissues, including the lungs, heart, and immune system, and it has been implicated in a number of different diseases and conditions, including asthma, chronic obstructive pulmonary disease (COPD), and certain types of cancer.
Adenosine kinase (AK) is an enzyme that plays a crucial role in the metabolism of adenosine, a purine nucleoside that is involved in various physiological processes, including neurotransmission, vasodilation, and immune function. AK catalyzes the conversion of adenosine to AMP (adenosine monophosphate) and ATP (adenosine triphosphate), which are essential energy sources for cells. This reaction is reversible, and AK can also convert AMP and ATP back to adenosine under certain conditions. In the medical field, AK is of interest because it is involved in several diseases and conditions, including cancer, cardiovascular disease, and neurological disorders. For example, AK has been shown to be overexpressed in some types of cancer, and its inhibition has been proposed as a potential therapeutic strategy. Additionally, AK has been implicated in the development of heart failure and stroke, and its activity has been shown to be modulated by various drugs and environmental factors.
Receptors, Adenosine A2 are a type of cell surface receptors that are activated by the neurotransmitter adenosine. These receptors are found in various tissues throughout the body, including the brain, heart, lungs, and blood vessels. There are several subtypes of Adenosine A2 receptors, including A2A, A2B, and A2C receptors. Each subtype has different functions and is activated by different concentrations of adenosine. Activation of Adenosine A2 receptors can have a variety of effects on the body, depending on the subtype and the tissue in which the receptors are located. For example, activation of A2A receptors in the brain can produce effects such as sedation, relaxation, and reduction of inflammation. Activation of A2B receptors in the lungs can cause bronchodilation, while activation of A2C receptors in the heart can produce effects such as vasodilation and reduction of heart rate. In the medical field, Adenosine A2 receptors are of interest for their potential therapeutic applications. For example, drugs that selectively activate A2A receptors are being investigated as potential treatments for Parkinson's disease, while drugs that activate A2B receptors are being studied for their potential to treat respiratory disorders such as asthma.
Receptors, Purinergic P1 are a type of protein receptors found on the surface of cells in the body that bind to a class of signaling molecules called purines. These receptors are also known as adenosine A1 receptors and are involved in a wide range of physiological processes, including regulation of blood pressure, heart rate, and sleep. Activation of these receptors can have both stimulatory and inhibitory effects on cellular activity, depending on the specific receptor subtype and the cell type in question. In the medical field, P1 purinergic receptors are of interest for their potential role in the treatment of various diseases, including cardiovascular disease, neurological disorders, and cancer.
Xanthines are a group of compounds that include caffeine, theophylline, and theobromine. They are naturally occurring alkaloids found in plants such as coffee, tea, and cocoa. In the medical field, xanthines are used as bronchodilators to treat conditions such as asthma and chronic obstructive pulmonary disease (COPD). They work by relaxing the muscles in the airways, allowing air to flow more easily. Xanthines can also be used to treat heart rhythm disorders and to prevent blood clots. However, they can have side effects such as nausea, vomiting, and increased heart rate, and may interact with other medications.
Adenosine monophosphate (AMP) is a nucleotide that plays a crucial role in various cellular processes, including energy metabolism, signal transduction, and gene expression. It is a component of the nucleic acids DNA and RNA and is synthesized from adenosine triphosphate (ATP) by the removal of two phosphate groups. In the medical field, AMP is often used as a biomarker for cellular energy status and is involved in the regulation of various physiological processes. For example, AMP levels are increased in response to cellular energy depletion, which can trigger the activation of AMP-activated protein kinase (AMPK), a key regulator of energy metabolism. Additionally, AMP is involved in the regulation of the sleep-wake cycle and has been shown to play a role in the development of various neurological disorders, including Alzheimer's disease and Parkinson's disease.
Theophylline is a medication that is used to treat a variety of respiratory conditions, including asthma, chronic obstructive pulmonary disease (COPD), and bronchitis. It works by relaxing the muscles in the airways, making it easier to breathe. Theophylline is available in both oral and inhaled forms, and it is usually taken on a regular basis to prevent symptoms from occurring. It is important to note that theophylline can have side effects, including nausea, vomiting, and an irregular heartbeat, and it should only be taken under the supervision of a healthcare provider.
Receptors, Purinergic are a type of cell surface receptors that are activated by the neurotransmitter adenosine triphosphate (ATP) and other purine derivatives. These receptors are found in various tissues throughout the body and play a role in many physiological processes, including pain perception, inflammation, and neurotransmission. There are several subtypes of purinergic receptors, including P1, P2X, and P2Y receptors, which differ in their structure, function, and distribution. Activation of these receptors can lead to a variety of cellular responses, including the release of other neurotransmitters, changes in ion channel activity, and the activation of intracellular signaling pathways.
2-Chloroadenosine is a modified form of adenosine, a naturally occurring nucleoside in the body. It is a white crystalline powder that is used in the medical field as a medication to treat certain types of blood disorders, such as sickle cell anemia and thalassemia. It works by increasing the production of fetal hemoglobin, which is a type of hemoglobin that is more stable and less prone to forming sickle-shaped red blood cells. 2-Chloroadenosine is typically administered intravenously and is usually given in combination with other medications. It is also being studied for its potential use in treating other conditions, such as cancer and heart disease.
Phenethylamines are a class of organic compounds that contain a phenyl ring and an ethylamine group. They are naturally occurring chemicals that can be found in a variety of plants and animals, including some species of insects and mammals. In the medical field, phenethylamines are sometimes used as research tools to study the brain and behavior. Some phenethylamines, such as amphetamines, have been used as stimulants to treat conditions such as narcolepsy and attention deficit hyperactivity disorder (ADHD). However, the use of phenethylamines as medications is generally limited due to their potential for abuse and side effects.
Phenylisopropyladenosine (PhIP) is a synthetic adenosine analog that has been studied for its potential therapeutic effects in various medical conditions. It is a white, odorless powder that is insoluble in water but soluble in organic solvents. PhIP is a selective A1 adenosine receptor agonist, which means that it binds to and activates the A1 receptor subtype of the adenosine receptor family. The A1 receptor is found in many different tissues throughout the body, including the brain, heart, and lungs, and plays a role in regulating a variety of physiological processes, such as blood pressure, heart rate, and inflammation. PhIP has been studied for its potential therapeutic effects in a number of medical conditions, including Parkinson's disease, Alzheimer's disease, and ischemic stroke. In preclinical studies, PhIP has been shown to improve cognitive function, reduce inflammation, and protect against neuronal damage in animal models of these conditions. However, more research is needed to fully understand the potential therapeutic effects of PhIP in humans and to determine the optimal dosage and administration route for this compound. Additionally, PhIP has been shown to have some side effects, including nausea, vomiting, and dizziness, which must be taken into account when considering its use as a therapeutic agent.
Inosine is a purine nucleoside that is naturally present in the body and is involved in various biological processes. In the medical field, inosine is used as a medication to treat certain types of heart failure. It works by increasing the production of adenosine triphosphate (ATP), which is the primary source of energy for cells in the body. Inosine is also being studied for its potential use in treating other conditions, such as chronic obstructive pulmonary disease (COPD) and certain types of cancer.
'5'-Nucleotidase is an enzyme that catalyzes the hydrolysis of 5'-phosphorylated nucleotides, such as adenosine 5'-monophosphate (AMP), to their corresponding nucleosides and inorganic phosphate. This enzyme is present in various tissues and cells throughout the body, including liver, kidney, and white blood cells. In the medical field, '5'-Nucleotidase plays a role in the metabolism of nucleotides and the regulation of purine and pyrimidine metabolism. It is also involved in the breakdown of nucleotides in the liver, which helps to maintain the balance of purines and pyrimidines in the body. Additionally, '5'-Nucleotidase has been implicated in the pathogenesis of certain diseases, such as liver cirrhosis and certain types of cancer. Therefore, the measurement of '5'-Nucleotidase activity in biological samples can be used as a diagnostic tool for these conditions.
Cyclic AMP (cAMP) is a signaling molecule that plays a crucial role in many cellular processes, including metabolism, gene expression, and cell proliferation. It is synthesized from adenosine triphosphate (ATP) by the enzyme adenylyl cyclase, and its levels are regulated by various hormones and neurotransmitters. In the medical field, cAMP is often studied in the context of its role in regulating cellular signaling pathways. For example, cAMP is involved in the regulation of the immune system, where it helps to activate immune cells and promote inflammation. It is also involved in the regulation of the cardiovascular system, where it helps to regulate heart rate and blood pressure. In addition, cAMP is often used as a tool in research to study cellular signaling pathways. For example, it is commonly used to activate or inhibit specific signaling pathways in cells, allowing researchers to study the effects of these pathways on cellular function.
Adenosine triphosphatases (ATPases) are a group of enzymes that hydrolyze adenosine triphosphate (ATP) to adenosine diphosphate (ADP) and inorganic phosphate (Pi). These enzymes play a crucial role in many cellular processes, including energy production, muscle contraction, and ion transport. In the medical field, ATPases are often studied in relation to various diseases and conditions. For example, mutations in certain ATPase genes have been linked to inherited disorders such as myopathy and neurodegenerative diseases. Additionally, ATPases are often targeted by drugs used to treat conditions such as heart failure, cancer, and autoimmune diseases. Overall, ATPases are essential enzymes that play a critical role in many cellular processes, and their dysfunction can have significant implications for human health.
Tubercidin is an antitubercular drug that was first isolated from the Chinese herb Sophora flavescens. It is a purine nucleoside analog that inhibits the growth of Mycobacterium tuberculosis, the causative agent of tuberculosis. Tubercidin is not commonly used as a first-line treatment for tuberculosis due to its toxicity and potential for drug resistance. However, it has been used in combination with other antitubercular drugs to treat drug-resistant tuberculosis. In addition to its antitubercular activity, tubercidin has also been shown to have antiviral and antifungal properties. It has been studied for its potential use in the treatment of viral infections such as influenza and herpes simplex virus, as well as fungal infections such as candidiasis.
Adenine nucleotides are a type of nucleotide that contains the nitrogenous base adenine (A) and a sugar-phosphate backbone. They are important molecules in the cell and play a crucial role in various biological processes, including energy metabolism and DNA synthesis. There are three types of adenine nucleotides: adenosine monophosphate (AMP), adenosine diphosphate (ADP), and adenosine triphosphate (ATP). AMP is the simplest form of adenine nucleotide, with only one phosphate group attached to the sugar. ADP has two phosphate groups attached to the sugar, while ATP has three phosphate groups. ATP is often referred to as the "energy currency" of the cell because it stores and releases energy through the transfer of phosphate groups. When ATP is broken down, one of its phosphate groups is released, releasing energy that can be used by the cell for various processes. When ATP is synthesized, energy is required to attach a new phosphate group to the molecule. Adenine nucleotides are involved in many cellular processes, including muscle contraction, nerve impulse transmission, and the synthesis of proteins and nucleic acids. They are also important in the regulation of gene expression and the maintenance of cellular homeostasis.
Nucleoside deaminases are enzymes that catalyze the hydrolysis of nitrogenous bases from nucleosides, resulting in the formation of a free base and a deaminated nucleoside. These enzymes play important roles in various biological processes, including DNA synthesis, RNA metabolism, and the regulation of gene expression. In the medical field, nucleoside deaminases have been studied for their potential therapeutic applications. For example, some nucleoside deaminases have been shown to be involved in the development of certain types of cancer, and inhibitors of these enzymes have been investigated as potential cancer treatments. Additionally, nucleoside deaminases have been used as targets for the development of antiviral drugs, as many viruses rely on the deamination of nucleosides to replicate their genetic material.
Coformycin is an antibiotic medication that is used to treat a variety of bacterial infections. It is a member of the aminoglycoside class of antibiotics, which work by binding to bacterial ribosomes and inhibiting protein synthesis. Coformycin is typically used to treat infections of the respiratory tract, urinary tract, and skin. It is usually administered intravenously, although it can also be given intramuscularly or orally in some cases. Side effects of coformycin may include nausea, vomiting, diarrhea, and hearing loss. It is important to note that coformycin can be toxic to the kidneys, so it should be used with caution in patients with kidney disease.
Dipyridamole is a medication that is used to prevent blood clots from forming in the blood vessels. It is also used to treat angina (chest pain caused by reduced blood flow to the heart) and to prevent blood clots after a heart attack or stroke. Dipyridamole works by increasing the amount of a substance called prostacyclin in the blood vessels, which helps to keep the blood vessels open and improve blood flow. It is usually taken by mouth in the form of a tablet or capsule.
Theobromine is a chemical compound that is found in cocoa beans, tea leaves, and some other plants. It is a xanthine alkaloid, which is a type of organic compound that is related to caffeine. Theobromine has a similar structure to caffeine, but it is less potent and has a longer-lasting effect. In the medical field, theobromine is sometimes used as a treatment for heart disease, high blood pressure, and other conditions. It is also used as a stimulant to help people stay awake and alert. However, theobromine can be toxic in large amounts, so it is important to use it carefully and under the guidance of a healthcare professional.
Pentostatin is a medication used to treat certain types of blood cancers, such as chronic myeloid leukemia (CML) and hairy cell leukemia. It works by inhibiting an enzyme called nucleoside diphosphate kinase, which is involved in the production of DNA and RNA in cancer cells. This leads to the death of cancer cells and slows the growth of tumors. Pentostatin is usually given as an intravenous infusion and is often used in combination with other medications to treat these types of blood cancers.
Adenosine Phosphosulfate (APS) is a molecule that plays a role in the metabolism of sulfur-containing amino acids, such as cysteine and methionine. It is a key intermediate in the process of sulfur assimilation, which is the incorporation of sulfur into amino acids for the synthesis of proteins. APS is synthesized in the liver and other tissues from adenosine triphosphate (ATP) and sulfate, which is obtained from dietary sources or produced by the body through the breakdown of sulfur-containing amino acids. APS is then used in the synthesis of cysteine and methionine, which are essential for the structure and function of proteins. In addition to its role in sulfur metabolism, APS has been shown to have a number of other functions in the body. For example, it has been implicated in the regulation of cell growth and differentiation, and it may play a role in the development of certain diseases, such as cancer and neurodegenerative disorders. Overall, APS is an important molecule in the metabolism of sulfur-containing amino acids and has a number of potential physiological functions.
In the medical field, purines are a type of organic compound that are found in many foods and are also produced by the body as a natural byproduct of metabolism. Purines are the building blocks of nucleic acids, which are the genetic material in all living cells. They are also important for the production of energy in the body. Purines are classified into two main types: endogenous purines, which are produced by the body, and exogenous purines, which are obtained from the diet. Foods that are high in purines include red meat, organ meats, seafood, and some types of beans and legumes. In some people, the body may not be able to properly break down and eliminate purines, leading to a buildup of uric acid in the blood. This condition, known as gout, can cause pain and inflammation in the joints. High levels of uric acid in the blood can also lead to the formation of kidney stones and other health problems.
Thioinosine is a synthetic nucleoside analog that is used in the treatment of certain viral infections, particularly cytomegalovirus (CMV) retinitis in people with AIDS. It is a prodrug that is converted to its active form, inosine, in the body. Thioinosine is administered intravenously and has been shown to be effective in reducing the frequency and severity of CMV retinitis episodes. It is also being studied for its potential use in the treatment of other viral infections, such as hepatitis B and C.
Triazines are a class of organic compounds that contain a three-membered nitrogen ring. They are commonly used as herbicides, pesticides, and fungicides. In the medical field, triazines have been studied for their potential use in the treatment of various conditions, including cancer, viral infections, and inflammatory diseases. Some specific examples of triazines that have been studied for medical use include protriptyline, a tricyclic antidepressant, and terbinafine, an antifungal medication. However, it is important to note that the use of triazines in medicine is still in the experimental stage, and more research is needed to fully understand their potential therapeutic benefits and risks.
Adenine is a nitrogenous base that is found in DNA and RNA. It is one of the four nitrogenous bases that make up the genetic code, along with guanine, cytosine, and thymine (in DNA) or uracil (in RNA). Adenine is a purine base, which means it has a double ring structure with a six-membered ring fused to a five-membered ring. It is one of the two purine bases found in DNA and RNA, the other being guanine. Adenine is important in the function of DNA and RNA because it forms hydrogen bonds with thymine (in DNA) or uracil (in RNA) to form the base pairs that make up the genetic code.
Deoxyadenosines are a type of nucleotide that are found in DNA. They are composed of a sugar molecule (deoxyribose), a phosphate group, and a nitrogenous base (adenine). Deoxyadenosines are one of the four nitrogenous bases that make up the genetic code in DNA, along with deoxythymidines, deoxyguanines, and deoxycytidines. They are important for the storage and transmission of genetic information in cells.
Aminophylline is a medication that is used to treat a variety of conditions related to breathing, such as asthma, chronic obstructive pulmonary disease (COPD), and bronchitis. It is a type of bronchodilator, which means that it helps to relax and widen the muscles in the airways, making it easier to breathe. Aminophylline is also sometimes used to treat heart rhythm disorders and to prevent blood clots from forming. It is usually taken by mouth, although it can also be given intravenously in some cases.
Nucleoside transport proteins are a group of proteins that are responsible for the transport of nucleosides, which are the building blocks of nucleic acids (DNA and RNA), across cell membranes. These proteins play a crucial role in the metabolism of nucleosides and are involved in various cellular processes, including DNA synthesis, RNA metabolism, and energy production. There are several types of nucleoside transport proteins, including concentrative nucleoside transporters (CNTs), equilibrative nucleoside transporters (ENTs), and nucleoside diphosphate kinases (NDPKs). CNTs are responsible for the active transport of nucleosides against their concentration gradient, while ENTs facilitate the passive diffusion of nucleosides across cell membranes. NDPKs, on the other hand, phosphorylate nucleosides to form nucleoside diphosphates, which are important intermediates in nucleic acid metabolism. Disruptions in the function of nucleoside transport proteins can lead to various diseases, including cancer, viral infections, and neurological disorders. For example, mutations in the CNT gene have been linked to inherited disorders of purine metabolism, such as Lesch-Nyhan syndrome and adenosine deaminase deficiency. Similarly, changes in the expression or function of ENTs have been implicated in the development of certain types of cancer, such as breast and lung cancer.
Hypoxanthine is a purine nucleoside that is naturally present in the body and is a precursor to the synthesis of the nucleotides adenine and guanine. It is also a component of the nucleic acids DNA and RNA. In the medical field, hypoxanthine is used as a diagnostic tool to measure the activity of the enzyme xanthine oxidase, which is involved in the metabolism of purines. It is also used as a treatment for certain genetic disorders, such as Lesch-Nyhan syndrome, which is characterized by high levels of uric acid in the blood and urine due to a deficiency in the enzyme hypoxanthine-guanine phosphoribosyltransferase.
Nucleotidases are enzymes that catalyze the hydrolysis of nucleotides, which are the building blocks of nucleic acids such as DNA and RNA. These enzymes are involved in various biological processes, including DNA synthesis, RNA metabolism, and nucleotide signaling. There are several types of nucleotidases, including phosphatases, nucleosidases, and nucleotidyltransferases. Phosphatases remove the phosphate group from the nucleotide, while nucleosidases cleave the sugar-phosphate bond, releasing the sugar and leaving behind the base. Nucleotidyltransferases add a nucleotide to another molecule, such as another nucleotide or a sugar. In the medical field, nucleotidases are important for understanding and treating various diseases. For example, defects in nucleotidases can lead to inherited disorders such as Lesch-Nyhan syndrome, which is caused by a deficiency in the enzyme hypoxanthine-guanine phosphoribosyltransferase (HGPRT). This enzyme is involved in purine metabolism and the deficiency leads to the accumulation of toxic metabolites and neurological symptoms. Nucleotidases are also important in cancer research, as they play a role in regulating cell proliferation and survival. Inhibitors of nucleotidases are being developed as potential cancer therapies, as they can block the growth of cancer cells by disrupting nucleotide metabolism.
Hypoxanthines are a group of purine derivatives that are important intermediates in the metabolism of purines. They are formed from the breakdown of nucleic acids, such as DNA and RNA, and are further metabolized to uric acid. In the medical field, hypoxanthines are often used as markers of purine metabolism and can be measured in blood or urine samples. Abnormal levels of hypoxanthines can be associated with a variety of medical conditions, including gout, kidney disease, and certain genetic disorders.
Triazoles are a class of synthetic organic compounds that contain a three-membered ring of nitrogen atoms. They are widely used in the medical field as antifungal agents, particularly for the treatment of invasive fungal infections such as candidiasis, aspergillosis, and cryptococcosis. The most commonly used triazole antifungal agents are fluconazole, itraconazole, voriconazole, and posaconazole. These drugs work by inhibiting the synthesis of ergosterol, a vital component of fungal cell membranes, which leads to the disruption of the membrane's integrity and ultimately the death of the fungal cell. Triazoles are also used in other medical applications, such as in the treatment of certain types of cancer, as well as in the development of new drugs for the treatment of other diseases.
Nucleosides are organic compounds that are composed of a nitrogenous base (either adenine, guanine, cytosine, thymine, uracil, or hypoxanthine) and a pentose sugar (ribose or deoxyribose). They are the building blocks of nucleic acids, such as DNA and RNA, which are essential for the storage and transmission of genetic information in living organisms. In the medical field, nucleosides are often used as components of antiviral and anticancer drugs, as well as in the treatment of certain genetic disorders.
Apyrase is a protein that hydrolyzes (breaks down) a type of molecule called adenosine triphosphate (ATP) into adenosine diphosphate (ADP) and inorganic phosphate (Pi). ATP is a molecule that serves as a source of energy for many cellular processes, and its hydrolysis is an important step in energy metabolism. In the medical field, apyrase is sometimes used as a research tool to study cellular energy metabolism and to investigate the role of ATP in various physiological and pathological processes. For example, apyrase has been shown to have anti-inflammatory and anti-thrombotic effects, and it is being investigated as a potential therapeutic agent for conditions such as heart disease and stroke. Additionally, apyrase has been used as a tool to study the function of ATP-sensitive potassium channels, which are important regulators of cell membrane potential and ion transport.
Adenylate cyclase is an enzyme that catalyzes the conversion of adenosine triphosphate (ATP) to cyclic adenosine monophosphate (cAMP), a second messenger molecule that plays a crucial role in many cellular signaling pathways. In the medical field, adenylate cyclase is often studied in the context of its role in regulating various physiological processes, including heart rate, blood pressure, and glucose metabolism. It is also involved in the regulation of hormone signaling, particularly in the endocrine system, where hormones such as adrenaline and thyroid hormones bind to specific receptors on the cell surface and activate adenylate cyclase, leading to the production of cAMP and the activation of downstream signaling pathways. Abnormalities in adenylate cyclase activity have been implicated in a number of diseases, including diabetes, hypertension, and certain forms of heart disease. As such, understanding the regulation and function of adenylate cyclase is an important area of research in the medical field.
Bucladesine is a medication that is used to treat certain types of cancer, including lung cancer and pancreatic cancer. It works by slowing the growth of cancer cells and preventing them from dividing and multiplying. Bucladesine is usually given as an injection into a vein, and it is typically administered in a hospital setting. It is important to note that bucladesine is not a cure for cancer, but it can help to slow the progression of the disease and improve the quality of life for people who are living with cancer.
In the medical field, ribonucleosides are the building blocks of ribonucleic acid (RNA). They are composed of a nitrogenous base (adenine, guanine, cytosine, or uracil), a five-carbon sugar (ribose), and a phosphate group. There are four types of ribonucleosides: adenosine, guanosine, cytidine, and uridine. These nucleosides are essential for the synthesis of RNA, which plays a crucial role in various cellular processes, including protein synthesis, gene expression, and regulation of cellular metabolism. In addition to their role in RNA synthesis, ribonucleosides have also been found to have therapeutic potential in the treatment of various diseases, including cancer, viral infections, and neurological disorders. For example, some ribonucleosides have been shown to have antiviral activity against HIV and hepatitis C virus, while others have been found to have neuroprotective effects in animal models of neurodegenerative diseases such as Alzheimer's and Parkinson's disease.
Adenosylhomocysteinase (AHCY) is an enzyme that plays a crucial role in the metabolism of the amino acid homocysteine. Homocysteine is a sulfur-containing amino acid that is produced as a byproduct of the metabolism of methionine, an essential amino acid. In the body, homocysteine is converted to cysteine through a series of enzymatic reactions. One of the enzymes involved in this process is AHCY, which catalyzes the hydrolysis of adenosylhomocysteine (AdoHcy) to homocysteine and adenosine. （hyperhomocysteinemia）。AHCY，。，AHCY。
Receptors, Purinergic P2 are a family of cell surface receptors that are activated by the neurotransmitter ATP (adenosine triphosphate) and other purine derivatives. These receptors are involved in a wide range of physiological processes, including neurotransmission, inflammation, and immune responses. There are several subtypes of P2 receptors, including P2X receptors, which are ligand-gated ion channels, and P2Y receptors, which are G protein-coupled receptors. P2 receptors are found in many different cell types and tissues throughout the body, and they play important roles in both normal physiology and disease.
Calcium is a chemical element with the symbol Ca and atomic number 20. It is a vital mineral for the human body and is essential for many bodily functions, including bone health, muscle function, nerve transmission, and blood clotting. In the medical field, calcium is often used to diagnose and treat conditions related to calcium deficiency or excess. For example, low levels of calcium in the blood (hypocalcemia) can cause muscle cramps, numbness, and tingling, while high levels (hypercalcemia) can lead to kidney stones, bone loss, and other complications. Calcium supplements are often prescribed to people who are at risk of developing calcium deficiency, such as older adults, vegetarians, and people with certain medical conditions. However, it is important to note that excessive calcium intake can also be harmful, and it is important to follow recommended dosages and consult with a healthcare provider before taking any supplements.
In the medical field, nucleotides are the building blocks of nucleic acids, which are the genetic material of cells. Nucleotides are composed of three components: a nitrogenous base, a pentose sugar, and a phosphate group. There are four nitrogenous bases in DNA: adenine (A), thymine (T), cytosine (C), and guanine (G). There are also four nitrogenous bases in RNA: adenine (A), uracil (U), cytosine (C), and guanine (G). The sequence of these nitrogenous bases determines the genetic information encoded in DNA and RNA.
8-Bromo Cyclic Adenosine Monophosphate (8-Br-cAMP) is a synthetic analog of cyclic adenosine monophosphate (cAMP), a signaling molecule that plays a crucial role in various cellular processes, including cell growth, differentiation, and metabolism. In the medical field, 8-Br-cAMP is used as a tool to study the effects of cAMP on cellular signaling pathways. It is often used in cell culture experiments to increase intracellular cAMP levels and investigate the downstream effects on gene expression, protein synthesis, and cellular behavior. 8-Br-cAMP is also used in some clinical applications, such as the treatment of certain types of cancer. It has been shown to inhibit the growth of some cancer cells by blocking the activity of certain enzymes involved in cell proliferation. However, more research is needed to fully understand the potential therapeutic applications of 8-Br-cAMP in medicine.
Colforsin is a synthetic decapeptide that mimics the action of adenosine, a naturally occurring molecule that plays a role in regulating various physiological processes in the body. It is used in the medical field as a bronchodilator, which means it helps to relax and widen the airways in the lungs, making it easier to breathe. Colforsin is typically administered as an aerosol or nebulizer solution and is used to treat conditions such as asthma, chronic obstructive pulmonary disease (COPD), and bronchitis. It works by activating adenosine receptors in the lungs, which leads to the release of calcium from the cells lining the airways, causing them to relax and open up.
Magnesium is a mineral that is essential for many bodily functions. It is involved in over 300 enzymatic reactions in the body, including the production of energy, the synthesis of proteins and DNA, and the regulation of muscle and nerve function. In the medical field, magnesium is used to treat a variety of conditions, including: 1. Hypomagnesemia: A deficiency of magnesium in the blood. This can cause symptoms such as muscle cramps, spasms, and seizures. 2. Cardiac arrhythmias: Abnormal heart rhythms that can be caused by low levels of magnesium. 3. Pre-eclampsia: A condition that can occur during pregnancy and is characterized by high blood pressure and protein in the urine. Magnesium supplementation may be used to treat this condition. 4. Chronic kidney disease: Magnesium is often lost in the urine of people with chronic kidney disease, and supplementation may be necessary to maintain adequate levels. 5. Alcohol withdrawal: Magnesium supplementation may be used to treat symptoms of alcohol withdrawal, such as tremors and seizures. 6. Muscle spasms: Magnesium can help to relax muscles and relieve spasms. 7. Anxiety and depression: Some studies have suggested that magnesium supplementation may help to reduce symptoms of anxiety and depression. Magnesium is available in various forms, including oral tablets, capsules, and intravenous solutions. It is important to note that high levels of magnesium can also be toxic, so it is important to use magnesium supplements under the guidance of a healthcare provider.
Caffeine is a naturally occurring stimulant that is found in many plants, including coffee beans, tea leaves, and cocoa beans. It is also added to many foods and beverages, such as coffee, tea, soda, and energy drinks, to enhance their flavor and provide a boost of energy. In the medical field, caffeine is used as a medication to treat a variety of conditions, including: 1. Sleep disorders: Caffeine is a stimulant that can help people stay awake and alert, making it useful for treating conditions such as insomnia and sleep apnea. 2. Headaches: Caffeine is a common ingredient in over-the-counter pain relievers, such as aspirin and ibuprofen, and is also used to treat migraines and tension headaches. 3. Fatigue: Caffeine can help to reduce fatigue and increase alertness, making it useful for people who work long hours or have trouble staying awake. 4. Parkinson's disease: Caffeine has been shown to improve symptoms of Parkinson's disease, including tremors and stiffness. 5. Asthma: Caffeine can help to relax the muscles in the airways, making it useful for people with asthma. It is important to note that caffeine can have side effects, including jitters, anxiety, and insomnia, and can interact with other medications. As with any medication, it is important to talk to a healthcare provider before using caffeine to treat a medical condition.
Hyperemia is a medical term that refers to an increase in blood flow to a particular area of the body, often resulting in redness, warmth, and swelling. It can occur in response to various stimuli, such as exercise, injury, inflammation, or emotional stress. In the medical field, hyperemia is often used to describe an increase in blood flow to a specific organ or tissue. For example, angina pectoris, a common symptom of coronary artery disease, is caused by hyperemia in the heart muscle. Similarly, hyperemia in the brain can cause headaches or migraines. Hyperemia can also be a sign of a more serious underlying condition, such as a blood clot, infection, or tumor. In these cases, it is important to identify the underlying cause of the hyperemia in order to provide appropriate treatment.
1-Methyl-3-isobutylxanthine, also known as IBMX, is a chemical compound that belongs to the xanthine family. It is a selective inhibitor of the enzyme phosphodiesterase type 4 (PDE4), which is involved in the breakdown of cyclic AMP (cAMP) in cells. In the medical field, IBMX is used as a research tool to study the effects of PDE4 inhibition on various physiological processes, including inflammation, pain, and airway smooth muscle contraction. It has also been investigated as a potential treatment for a variety of conditions, including asthma, chronic obstructive pulmonary disease (COPD), and psoriasis. However, IBMX is not currently approved for use as a therapeutic agent in humans, as it can have significant side effects, including nausea, vomiting, diarrhea, and increased heart rate. Additionally, prolonged use of IBMX can lead to the development of tolerance and dependence.
Norbornanes are a class of organic compounds that are derived from the bicyclo[2.2.1]heptane ring system. They are typically used as intermediates in the synthesis of other organic compounds, and have also been studied for their potential medicinal applications. In the medical field, norbornanes have been investigated for their potential use as anti-inflammatory agents, as well as for their potential to treat a variety of neurological disorders, including Alzheimer's disease and Parkinson's disease. Some studies have also suggested that norbornanes may have antitumor properties, although more research is needed to confirm these findings. It is important to note that norbornanes are not currently approved for use as medical treatments, and more research is needed to fully understand their potential therapeutic effects and potential side effects.
Isoproterenol is a synthetic beta-adrenergic agonist that is used in the medical field as a medication. It is a drug that mimics the effects of adrenaline (epinephrine) and can be used to treat a variety of conditions, including asthma, heart failure, and bradycardia (a slow heart rate). Isoproterenol works by binding to beta-adrenergic receptors on the surface of cells, which triggers a cascade of events that can lead to increased heart rate, relaxation of smooth muscle, and dilation of blood vessels. This can help to improve blood flow and oxygen delivery to the body's tissues, and can also help to reduce inflammation and bronchoconstriction (narrowing of the airways). Isoproterenol is available in a variety of forms, including tablets, inhalers, and intravenous solutions. It is typically administered as a short-acting medication, although longer-acting formulations are also available. Side effects of isoproterenol can include tremors, palpitations, and increased heart rate, and the drug may interact with other medications that affect the heart or blood vessels.
S-Adenosylhomocysteine (SAH) is a molecule that is produced as a byproduct of the metabolism of the amino acid methionine. It is formed when the enzyme methionine adenosyltransferase (MAT) transfers an adenosine group from ATP to methionine, producing S-adenosylmethionine (SAM) and SAH. SAH is a potent inhibitor of the enzyme methionine adenosyltransferase, which is responsible for the synthesis of SAM. SAM is a critical molecule that is involved in a wide range of biological processes, including the synthesis of proteins, DNA, and RNA, as well as the regulation of gene expression and the detoxification of harmful substances in the body. SAH，、。，SAH。
Purine nucleosides are a type of nucleoside that contains a purine base, which is one of two types of nitrogen-containing bases found in DNA and RNA. Purine nucleosides are important components of nucleic acids, which are the building blocks of DNA and RNA. They are also involved in various cellular processes, including energy metabolism and the synthesis of nucleic acids. In the medical field, purine nucleosides are used as medications to treat certain types of cancer and to manage symptoms of certain viral infections. They are also being studied for their potential use in the treatment of other conditions, such as autoimmune diseases and neurological disorders.
Dinucleoside phosphates (DNP) are a class of compounds that consist of two nucleosides (a sugar and a nitrogenous base) joined together by a phosphate group. They are found naturally in cells and play important roles in various biological processes, including signal transduction, gene expression, and energy metabolism. In the medical field, DNP have been studied for their potential therapeutic applications. For example, some DNP have been shown to have anti-inflammatory and anti-cancer effects, and they are being investigated as potential treatments for a variety of diseases, including cancer, diabetes, and neurodegenerative disorders. Additionally, DNP have been used as research tools to study the function of nucleoside signaling pathways in cells.
Equilibrative Nucleoside Transporter 1 (ENT1) is a protein that plays a role in the transport of nucleosides, which are the building blocks of DNA and RNA, across cell membranes. ENT1 is a member of the equilibrative nucleoside transporter family, which is involved in the transport of a wide range of nucleosides and nucleoside analogs. ENT1 is expressed in many tissues throughout the body, including the brain, liver, and kidneys. In the brain, ENT1 is involved in the transport of adenosine, a neurotransmitter that plays a role in regulating brain function. In the liver and kidneys, ENT1 is involved in the elimination of nucleosides from the body. In the medical field, ENT1 is of interest because it is a target for the development of drugs for the treatment of a variety of conditions, including cancer, viral infections, and neurological disorders. For example, some nucleoside analogs, which are drugs that are structurally similar to nucleosides but have different chemical properties, are used to treat viral infections such as HIV and hepatitis B by inhibiting the activity of ENT1 and preventing the transport of nucleosides into cells.
Adenosine diphosphate (ADP) sugars are a type of sugar molecule that is involved in various biological processes, including energy metabolism and the synthesis of nucleic acids such as DNA and RNA. ADP sugars are formed by the addition of a phosphate group to adenosine, a nucleoside that is a component of nucleotides. They are important intermediates in the metabolism of glucose and other sugars, and are also involved in the synthesis of other important molecules such as ATP (adenosine triphosphate), the primary energy currency of the cell. In the medical field, ADP sugars are often studied in the context of diseases such as diabetes, which involve disruptions in glucose metabolism.
Thionucleotides are a type of nucleotide that contain a sulfur atom in place of the oxygen atom that is typically found in the sugar-phosphate backbone of nucleotides. They are an important component of the genetic material of certain bacteria and archaea, and are also used in the synthesis of certain drugs and other compounds. Thionucleotides are synthesized using a variety of methods, including chemical synthesis and enzymatic synthesis. They have a number of unique properties that make them useful in a variety of applications, including their ability to form stable bonds with other molecules and their ability to undergo a variety of chemical reactions.
Guanosine is a nucleoside that is composed of the nitrogenous base guanine and the sugar ribose. It is a building block of nucleic acids, such as DNA and RNA, and plays a crucial role in various cellular processes. In the medical field, guanosine is used as a medication to treat certain types of cancer, such as acute myeloid leukemia and non-Hodgkin's lymphoma. It works by inhibiting the growth and proliferation of cancer cells. Guanosine is also used as a supplement to support immune function and to treat certain viral infections, such as cytomegalovirus (CMV) and herpes simplex virus (HSV). It is believed to work by stimulating the production of immune cells and by inhibiting the replication of viruses. In addition, guanosine is involved in the regulation of various cellular processes, such as gene expression, signal transduction, and energy metabolism. It is also a precursor of the nucleotide guanosine triphosphate (GTP), which plays a key role in many cellular processes, including protein synthesis and cell division.
Equilibrative Nucleoside Transporter 2 (ENT2) is a protein that plays a role in the transport of nucleosides and nucleobases across cell membranes. It is a member of the equilibrative nucleoside transporter (ENT) family, which is involved in the uptake and efflux of nucleosides and nucleobases in cells. ENT2 is expressed in a variety of tissues, including the liver, kidney, and brain, and is thought to play a role in the metabolism of nucleosides and nucleobases in these tissues. In the medical field, ENT2 is of interest because it has been implicated in the development of certain diseases, including cancer and neurological disorders. For example, some studies have suggested that ENT2 may play a role in the development of drug resistance in cancer cells, and that it may be a potential target for the development of new cancer therapies. Additionally, some research has suggested that ENT2 may be involved in the development of neurological disorders such as multiple sclerosis and Parkinson's disease.
Phosphotransferases are a group of enzymes that transfer a phosphate group from one molecule to another. These enzymes play important roles in various metabolic pathways, including glycolysis, the citric acid cycle, and the pentose phosphate pathway. There are several types of phosphotransferases, including kinases, which transfer a phosphate group from ATP to another molecule, and phosphatases, which remove a phosphate group from a molecule. In the medical field, phosphotransferases are important for understanding and treating various diseases, including cancer, diabetes, and cardiovascular disease. For example, some kinases are involved in the regulation of cell growth and division, and their overactivity has been linked to the development of cancer. Similarly, changes in the activity of phosphatases can contribute to the development of diabetes and other metabolic disorders. Phosphotransferases are also important targets for drug development. For example, some drugs work by inhibiting the activity of specific kinases or phosphatases, in order to treat diseases such as cancer or diabetes.
Glyburide is a medication used to treat type 2 diabetes. It belongs to a class of drugs called sulfonylureas, which work by stimulating the pancreas to produce more insulin. Glyburide is typically used in combination with diet and exercise to help lower blood sugar levels in people with diabetes. It can also be used alone in people who are not able to control their blood sugar levels with diet and exercise alone. Glyburide can cause side effects such as low blood sugar, nausea, and headache. It is important to take glyburide exactly as prescribed by a healthcare provider and to monitor blood sugar levels regularly while taking this medication.
Suramin is an antiprotozoal drug that is used to treat African trypanosomiasis (sleeping sickness) caused by the parasite Trypanosoma brucei. It works by binding to the surface of the parasite and disrupting its ability to feed on red blood cells. Suramin is also being studied for its potential use in treating other parasitic infections, such as leishmaniasis and schistosomiasis. It is typically administered intravenously or intramuscularly.
Anoxia is a medical condition characterized by a lack of oxygen in the body's tissues. This can occur due to a variety of factors, including low oxygen levels in the air, reduced blood flow to the tissues, or a lack of oxygen-carrying red blood cells. Anoxia can lead to a range of symptoms, including confusion, dizziness, shortness of breath, and loss of consciousness. In severe cases, anoxia can be life-threatening and may require immediate medical attention.
3',5'-Cyclic-AMP phosphodiesterases (PDEs) are a family of enzymes that play a crucial role in regulating the levels of cyclic AMP (cAMP) in the body. cAMP is a signaling molecule that is involved in a wide range of cellular processes, including cell growth, differentiation, and metabolism. PDEs are responsible for breaking down cAMP into inactive products, thereby regulating the levels of this signaling molecule in the body. There are 11 different subtypes of PDEs, each with its own specific substrate specificity and tissue distribution. In the medical field, PDEs are of particular interest because they are involved in the regulation of many different physiological processes, including the cardiovascular system, the nervous system, and the immune system. In addition, PDEs are the targets of many drugs, including some used to treat conditions such as erectile dysfunction, asthma, and heart failure.
Formycins are a group of antibiotics that are produced by various species of fungi, including Aspergillus and Penicillium. They are structurally related to penicillins and are characterized by the presence of a beta-lactam ring. Formycins have a broad spectrum of activity against gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA), and are also effective against some gram-negative bacteria and fungi. They are used in the treatment of a variety of infections, including skin and soft tissue infections, respiratory tract infections, and urinary tract infections. Formycins are generally well-tolerated, but like other antibiotics, they can cause side effects such as nausea, vomiting, and diarrhea.
Cyclic AMP-dependent protein kinases (also known as cAMP-dependent protein kinases or PKA) are a family of enzymes that play a crucial role in regulating various cellular processes in the body. These enzymes are activated by the presence of cyclic AMP (cAMP), a second messenger molecule that is produced in response to various stimuli, such as hormones, neurotransmitters, and growth factors. PKA is a heterotetrameric enzyme composed of two regulatory subunits and two catalytic subunits. The regulatory subunits bind to cAMP and prevent the catalytic subunits from phosphorylating their target proteins. When cAMP levels rise, the regulatory subunits are activated and release the catalytic subunits, allowing them to phosphorylate their target proteins. PKA is involved in a wide range of cellular processes, including metabolism, gene expression, cell proliferation, and differentiation. It phosphorylates various proteins, including enzymes, transcription factors, and ion channels, leading to changes in their activity and function. In the medical field, PKA plays a critical role in various diseases and disorders, including cancer, diabetes, and cardiovascular disease. For example, PKA is involved in the regulation of insulin secretion in pancreatic beta cells, and its dysfunction has been implicated in the development of type 2 diabetes. PKA is also involved in the regulation of blood pressure and heart function, and its dysfunction has been linked to the development of hypertension and heart disease.
Purine-Nucleoside Phosphorylase (PNP) is an enzyme that plays a crucial role in the metabolism of purine nucleosides, which are the building blocks of DNA and RNA. PNP catalyzes the conversion of purine nucleosides to their corresponding nucleoside monophosphates, which are then used in various metabolic pathways. In the medical field, PNP deficiency is a rare genetic disorder that affects the metabolism of purine nucleosides. This deficiency can lead to the accumulation of toxic levels of purine nucleosides and their breakdown products in the body, which can cause a range of symptoms, including neurological problems, liver damage, and bone marrow failure. PNP deficiency is typically diagnosed through blood tests that measure the activity of the enzyme in the blood and bone marrow. Treatment for PNP deficiency typically involves the use of medications that help to lower the levels of purine nucleosides in the body, such as allopurinol and febuxostat. In severe cases, bone marrow transplantation may be necessary to replace the defective bone marrow cells.
AMP deaminase (AMPD) is an enzyme that catalyzes the conversion of adenosine monophosphate (AMP) to inosine monophosphate (IMP). This enzyme plays a crucial role in the regulation of cellular energy metabolism by controlling the levels of AMP and IMP in the cell. In the medical field, AMPD is often studied in the context of various diseases and disorders, including cancer, diabetes, and heart disease. For example, high levels of AMPD have been associated with an increased risk of certain types of cancer, while low levels of AMPD have been linked to insulin resistance and type 2 diabetes. Additionally, AMPD has been shown to play a role in the regulation of blood pressure and heart function, making it an important target for the development of new treatments for cardiovascular disease.
Potassium channels are a type of ion channel found in the cell membrane of many types of cells, including neurons, muscle cells, and epithelial cells. These channels are responsible for regulating the flow of potassium ions (K+) in and out of the cell, which is important for maintaining the cell's resting membrane potential and controlling the generation and propagation of electrical signals in the cell. Potassium channels are classified into several different types based on their biophysical properties, such as their voltage sensitivity, pharmacology, and gating mechanisms. Some of the most well-known types of potassium channels include voltage-gated potassium channels, inwardly rectifying potassium channels, and leak potassium channels. In the medical field, potassium channels play a critical role in many physiological processes, including muscle contraction, neurotransmission, and regulation of blood pressure. Abnormalities in potassium channel function can lead to a variety of diseases and disorders, such as epilepsy, hypertension, and cardiac arrhythmias. Therefore, understanding the structure and function of potassium channels is important for developing new treatments for these conditions.
Potassium is a mineral that is essential for the proper functioning of many bodily processes. It is the most abundant positively charged ion in the body and plays a crucial role in maintaining fluid balance, regulating muscle contractions, transmitting nerve impulses, and supporting the proper functioning of the heart. In the medical field, potassium is often measured in blood tests to assess its levels and determine if they are within the normal range. Abnormal potassium levels can be caused by a variety of factors, including certain medications, kidney disease, hormonal imbalances, and certain medical conditions such as Addison's disease or hyperaldosteronism. Low levels of potassium (hypokalemia) can cause muscle weakness, cramps, and arrhythmias, while high levels (hyperkalemia) can lead to cardiac arrhythmias, muscle weakness, and even cardiac arrest. Treatment for potassium imbalances typically involves adjusting the patient's diet or administering medications to correct the imbalance.
Ribose is a type of sugar molecule that is an important component of RNA (ribonucleic acid) and ATP (adenosine triphosphate), two molecules that play crucial roles in cellular metabolism and genetic information transfer. In the medical field, ribose is sometimes used as a dietary supplement to support energy production and athletic performance. It is also used in the treatment of certain medical conditions, such as chronic fatigue syndrome and fibromyalgia, where it may help to reduce fatigue and improve physical function.
Dilazep is a brand name for the medication diltiazem, which is a calcium channel blocker. Calcium channel blockers are a type of medication that is used to treat high blood pressure, chest pain (angina), and certain heart rhythm disorders. They work by relaxing the muscles in blood vessels, which allows blood to flow more easily and reduces blood pressure. Dilazep is available in both oral tablet and extended-release capsule forms. It is usually taken once or twice a day, with or without food. Dilazep can cause side effects such as headache, dizziness, and constipation. It is important to follow the instructions of your healthcare provider when taking Dilazep.
Uridine Triphosphate (UTP) is a nucleotide that plays a crucial role in various biological processes, including energy metabolism, DNA and RNA synthesis, and signal transduction. In the medical field, UTP is often used as a medication to treat certain conditions, such as respiratory distress syndrome, sepsis, and liver failure. It is also used as a supplement to support overall health and wellness. UTP is a precursor to uridine diphosphate (UDP), which is involved in the synthesis of various lipids and glycosaminoglycans.
Dideoxyadenosine (ddA) is a nucleoside analog that is used in the treatment of certain viral infections, particularly HIV and hepatitis B. It works by inhibiting the activity of the viral reverse transcriptase enzyme, which is essential for the replication of these viruses. ddA is typically administered as a part of combination therapy with other antiretroviral drugs. It is also being studied for its potential use in the treatment of other viral infections and cancer.
Isopentenyladenosine (iPA) is a type of nucleoside that is found in plants and some microorganisms. It is a derivative of adenosine, which is a nucleoside that is involved in many important biological processes, including energy metabolism and gene expression. In the medical field, iPA has been studied for its potential therapeutic effects. For example, it has been shown to have anti-inflammatory and immunomodulatory properties, and it may be useful in the treatment of a variety of conditions, including cancer, autoimmune diseases, and viral infections. However, more research is needed to fully understand the potential benefits and risks of iPA, and to determine the optimal dosages and treatment regimens for different conditions.
Adenosine thiamine triphosphate
Adenosine A1 receptor
Adenosine diphosphate ribose
Adenosine A2A receptor
Adenosine receptor agonist
Adenosine A3 receptor
Adenosine receptor antagonist
Adenosine A2B receptor
Adenosine deaminase deficiency
Adenosine thiamine diphosphate
Cyclic adenosine monophosphate
Adenosine A2 receptor
Adenosine reuptake inhibitor
Adenosine diphosphate receptor inhibitor
Adenosine deaminase 2 deficiency
Adenosine Tri-Phosphate (band)
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- Adenosine triphosphate (ATP) Complete Contamination Monitoring System measures cleanliness and microbial contamination processes on surfaces, including surgical instruments, scopes, washer-disinfectors, examination rooms, operating rooms, restrooms, waiting rooms and surfaces that contamination can grow and possibly affect patient and staff health. (va.gov)
Effect of adenosine2
- We used whole-cell patch-clamp recordings in in vitro rat brain slices to investigate the effect of adenosine on identified cholinergic and noncholinergic neurons of the magnocellular preoptic nucleus and substantia innominata. (nih.gov)
- The most profound effect of adenosine is the induction of an A-V block within 10 to 20 seconds of administra-tion. (brainkart.com)
- Adenosine deaminase deficiency is very rare and is estimated to occur in approximately 1 in 200,000 to 1,000,000 newborns worldwide. (medlineplus.gov)
- Adenosine deaminase deficiency is caused by mutations in the ADA gene. (medlineplus.gov)
- Adenosine deaminase deficiency: unanticipated benefits from the study of a rare immunodeficiency. (medlineplus.gov)
- The following is a summary of "Updated Management Guidelines for Adenosine Deaminase Deficiency," published in the June 2023 issue of Allergy and Clinical Immunology: In Practice by Grunebaum et al. (physiciansweekly.com)
- Erowid.org: Erowid Reference 3068 : Adenosine Cyclic 3',5'-Monophosphate in the Liver Fluke, fasciola hepatica. (erowid.org)
- In the presence of O.i mM 5HT, AC activity in the fluke particles was inhibited by 0.5 mcM LSD, and LSD also antagonized the 5HT stimulated increase in cyclic AMP levels, Adenine, adenosine, histamine (Calbiochem), adrenaline (Mann), tryptophan, dopamine, GTP (Sigma - Chem. (erowid.org)
- Furthermore, PDRN treatment enhanced the concentration of cyclic adenosine-3,5'-monophosphate (cAMP) as well as phosphorylation of cAMP response element-binding protein (p-CREB). (iasp-pain.org)
- Application of the A1 receptor antagonist 8-cyclo-pentyl-theophylline (200 nM) blocked the effects of adenosine. (nih.gov)
- This invention relates to a method of decreasing intraocular pressure by administrating an A3 subtype adenosine receptor antagonist, a calmodulin antagonist or an antiestrogen such as tamoxifen. (nih.gov)
- In order to confirm the participation of the adenosine A2A receptor in the effects mediated by PDRN, 8 mg/kg 7-dimethyl-1-propargylxanthine (DMPX), adenosine A2A receptor antagonist, was treated with PDRN. (iasp-pain.org)
- Clinicians should avoid using the imaging agents regadenoson ( Lexiscan , Astellas Pharma US) and adenosine ( Adenoscan , Astellas Pharma US) for cardiac nuclear stress tests of patients with signs or symptoms of unstable angina or cardiovascular instability because the drugs may increase their risk for a fatal heart attack, the US Food and Drug Administration (FDA) announced today. (medscape.com)
- green tea decreases effects of adenosine by unspecified interaction mechanism. (medscape.com)
- sevelamer decreases levels of adenosine by increasing elimination. (medscape.com)
- theophylline decreases effects of adenosine by pharmacodynamic antagonism. (medscape.com)
- Adenosine decreases the effects of chemicals on the heart. (foundhealth.com)
- In addition, adenosine decreases Tumor Necrosis Factor production by monocytes , which was partially abolished with the blockage of the A2a receptor. (bvsalud.org)
- Adenosine (Adenocard) is an endogenous nucleoside that is a product of the metabolism of adenosine triphos-phate. (brainkart.com)
Severe combined immunod2
- In the first group adenosine, via activation of postsynaptic A1 receptors, reduced spontaneous firing via inhibition of the hyperpolarization-activated cation current. (nih.gov)
- Adenosine receptors are found on myocytes in the atria and sinoatrial and A-V nodes. (brainkart.com)
- Methylxanthines antagonize the effects of adenosine via blockade of the adenosine receptors. (brainkart.com)
- A convenience sampling of peripheral blood mononuclear cells from Plasmodium vivax -infected patients and healthy donors were tested for the characterization of cytokine and adenosine production and the expression of ectonucleotidases and purinergic receptors . (bvsalud.org)
- The function of the adenosine deaminase enzyme is to eliminate a molecule called deoxyadenosine, which is generated when DNA is broken down. (medlineplus.gov)
- Adenosine deaminase converts deoxyadenosine, which can be toxic to lymphocytes, to another molecule called deoxyinosine that is not harmful. (medlineplus.gov)
- Adenosine is an important antiinflammatory molecule in tissue inflammation, and adenosine 2A receptor (A2AR) agonists protect kidneys from IRI through their actions on leukocytes. (jci.org)
- This initial interaction (platelet adhesion) sets the stage for other adhesive reactions that allow the platelets to interact with other agonists in the vicinity of vessel injury, such as adenosine 5'-diphosphate (ADP), subendothelial collagen, and thrombin. (medscape.com)
- Rarely, an adenosine bo-lus injection is accompanied by atrial fibrillation or ven-tricular tachyarrhythmias. (brainkart.com)
- L'agrégation plaquettaire induite par le collagène dans des échantillons de plasma riche en plaquettes de 14 lapins sains a été mesurée par turbidimétrie en utilisant un agrégomètre, avant et une heure après une injection intra- veineuse d'alun. (who.int)
- Adenosine deaminase (ADA) is a protein produced by body cells and is associated with lymphocyte activation. (thyrocare.com)
- If these maneuvers are ineffective, treatment is with IV adenosine or nondihydropyridine calcium channel blockers for narrow QRS rhythms or for wide QRS rhythms known to be a reentrant SVT with aberrant conduction that requires atrioventricular nodal conduction. (msdmanuals.com)
- In the basal forebrain, adenosine accumulates during wakefulness and, when locally applied, suppresses neuronal activity and promotes sleep. (nih.gov)
- Adenosine A2A receptor agonist, polydeoxyribonucleotide (PDRN), suppresses the secretion of pro-inflammatory cytokines and exhibits anti-inflammatory effect. (iasp-pain.org)
- As indicated previously, the use of adenosine in asthmatic patients may exacerbate the asthmatic symptoms. (brainkart.com)
- Monocytes express high levels of ectonucleotidases, indicating their important role in extracellular ATP modulation and consequently in adenosine production . (bvsalud.org)
- The administration of a bolus dose of adenosine is asso-ciated with a biphasic pressor response. (brainkart.com)
- The U.S. Food and Drug Administration (FDA) has approved BRCA genetic tests as companion diagnostics to guide cancer treatment with poly adenosine diphosphate-ribose polymerase (PARP) inhibitors . (cdc.gov)
- These results demonstrate that, in the magnocellular preoptic nucleus and substantia innominata region of the basal forebrain, adenosine inhibits both cholinergic neurons and a subset of noncholinergic neurons. (nih.gov)
- The labels for both regadenoson and adenosine had previously warned of the risk for MI. (medscape.com)
- The agency approved adenosine in 1995 and regadenoson in 2008 for radionuclide myocardial perfusion imaging in patients who cannot undergo exercise stress testing. (medscape.com)
- Patients with second- or third-degree A-V block should not receive adenosine. (brainkart.com)
- Ces résultats semblent indiquer que l'utilisation de l'alun en tant qu'antiplaquettaire oral pourrait faire l'objet d'études complémentaires, en tenant compte des effets secondaires éventuels notamment chez les patients dont la fonction rénale est altérée. (who.int)
- Six MI cases and 27 deaths turned up for adenosine following that drug's debut. (medscape.com)
- This test measures the amount of adenosine deaminase in pleural fluid. (thyrocare.com)
- Adenosine has been proposed as a homeostatic "sleep factor" that promotes the transition from waking to sleep by affecting several sleep-wake regulatory systems. (nih.gov)