Cyclic AMP: An adenine nucleotide containing one phosphate group which is esterified to both the 3'- and 5'-positions of the sugar moiety. It is a second messenger and a key intracellular regulator, functioning as a mediator of activity for a number of hormones, including epinephrine, glucagon, and ACTH.Adenosine: A nucleoside that is composed of ADENINE and D-RIBOSE. Adenosine or adenosine derivatives play many important biological roles in addition to being components of DNA and RNA. Adenosine itself is a neurotransmitter.Purinergic P1 Receptor Antagonists: Compounds that bind to and block the stimulation of PURINERGIC P1 RECEPTORS.Receptors, Purinergic P1: A class of cell surface receptors that prefer ADENOSINE to other endogenous PURINES. Purinergic P1 receptors are widespread in the body including the cardiovascular, respiratory, immune, and nervous systems. There are at least two pharmacologically distinguishable types (A1 and A2, or Ri and Ra).Adenosine A1 Receptor Antagonists: Compounds that bind to and block the stimulation of ADENOSINE A1 RECEPTORS.Receptor, Adenosine A1: A subtype of ADENOSINE RECEPTOR that is found expressed in a variety of tissues including the BRAIN and DORSAL HORN NEURONS. The receptor is generally considered to be coupled to the GI, INHIBITORY G-PROTEIN which causes down regulation of CYCLIC AMP.Colforsin: Potent activator of the adenylate cyclase system and the biosynthesis of cyclic AMP. From the plant COLEUS FORSKOHLII. Has antihypertensive, positive inotropic, platelet aggregation inhibitory, and smooth muscle relaxant activities; also lowers intraocular pressure and promotes release of hormones from the pituitary gland.Purinergic P1 Receptor Agonists: Compounds that bind to and stimulate PURINERGIC P1 RECEPTORS.Kinetics: The rate dynamics in chemical or physical systems.Dose-Response Relationship, Drug: The relationship between the dose of an administered drug and the response of the organism to the drug.Apiaceae: A large plant family in the order Apiales, also known as Umbelliferae. Most are aromatic herbs with alternate, feather-divided leaves that are sheathed at the base. The flowers often form a conspicuous flat-topped umbel. Each small individual flower is usually bisexual, with five sepals, five petals, and an enlarged disk at the base of the style. The fruits are ridged and are composed of two parts that split open at maturity.Acorus: A plant genus of the family ACORACEAE, order Arales, subclass Arecidae most notable for Acorus calamus L. root which contains asarone and has been used in TRADITIONAL MEDICINE.Pimenta: A plant genus in the family MYRTACEAE, order Myrtales, subclass Rosidae. It is best known for allspice from the dried berry of Pimenta diocia.Piper nigrum: A plant species in the PIPERACEAE plant family. It is a common spice on foods and is used medicinally to increase gastrointestinal assimilation of other supplements and drugs. Piperine is a key component. Black pepper is picked unripe and heaped for a few days to ferment. White Pepper is the ripe fruit dehulled by maceration in water.Myrtaceae: The myrtle plant family of the order Myrtales. It includes several aromatic medicinal plants such as EUCALYPTUS.Acoraceae: A plant family of the order Arales, subclass Arecidae, class Liliopsida (monocot).Black Pepper: A common spice from fruit of PIPER NIGRUM. Black pepper is picked unripe and heaped for a few days to ferment. White Pepper is the ripe fruit dehulled by maceration in water. Piperine is a key component used medicinally to increase gastrointestinal assimilation of other supplements and drugs.Spices: The dried seeds, bark, root, stems, buds, leaves, or fruit of aromatic plants used to season food.Cuscuta: A plant genus of the family Cuscutaceae. It is a threadlike climbing parasitic plant that is used in DRUGS, CHINESE HERBAL.Asteraceae: A large plant family of the order Asterales, subclass Asteridae, class Magnoliopsida. The family is also known as Compositae. Flower petals are joined near the base and stamens alternate with the corolla lobes. The common name of "daisy" refers to several genera of this family including Aster; CHRYSANTHEMUM; RUDBECKIA; TANACETUM.tau Proteins: Microtubule-associated proteins that are mainly expressed in neurons. Tau proteins constitute several isoforms and play an important role in the assembly of tubulin monomers into microtubules and in maintaining the cytoskeleton and axonal transport. Aggregation of specific sets of tau proteins in filamentous inclusions is the common feature of intraneuronal and glial fibrillar lesions (NEUROFIBRILLARY TANGLES; NEUROPIL THREADS) in numerous neurodegenerative disorders (ALZHEIMER DISEASE; TAUOPATHIES).Tauopathies: Neurodegenerative disorders involving deposition of abnormal tau protein isoforms (TAU PROTEINS) in neurons and glial cells in the brain. Pathological aggregations of tau proteins are associated with mutation of the tau gene on chromosome 17 in patients with ALZHEIMER DISEASE; DEMENTIA; PARKINSONIAN DISORDERS; progressive supranuclear palsy (SUPRANUCLEAR PALSY, PROGRESSIVE); and corticobasal degeneration.Neurofibrillary Tangles: Abnormal structures located in various parts of the brain and composed of dense arrays of paired helical filaments (neurofilaments and microtubules). These double helical stacks of transverse subunits are twisted into left-handed ribbon-like filaments that likely incorporate the following proteins: (1) the intermediate filaments: medium- and high-molecular-weight neurofilaments; (2) the microtubule-associated proteins map-2 and tau; (3) actin; and (4) UBIQUITINS. As one of the hallmarks of ALZHEIMER DISEASE, the neurofibrillary tangles eventually occupy the whole of the cytoplasm in certain classes of cell in the neocortex, hippocampus, brain stem, and diencephalon. The number of these tangles, as seen in post mortem histology, correlates with the degree of dementia during life. Some studies suggest that tangle antigens leak into the systemic circulation both in the course of normal aging and in cases of Alzheimer disease.Neurodegenerative Diseases: Hereditary and sporadic conditions which are characterized by progressive nervous system dysfunction. These disorders are often associated with atrophy of the affected central or peripheral nervous system structures.Alzheimer Disease: A degenerative disease of the BRAIN characterized by the insidious onset of DEMENTIA. Impairment of MEMORY, judgment, attention span, and problem solving skills are followed by severe APRAXIAS and a global loss of cognitive abilities. The condition primarily occurs after age 60, and is marked pathologically by severe cortical atrophy and the triad of SENILE PLAQUES; NEUROFIBRILLARY TANGLES; and NEUROPIL THREADS. (From Adams et al., Principles of Neurology, 6th ed, pp1049-57)alpha-Synuclein: A synuclein that is a major component of LEWY BODIES that plays a role in neurodegeneration and neuroprotection.Neurons: The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.Neurofibrils: The delicate interlacing threads, formed by aggregations of neurofilaments and neurotubules, coursing through the CYTOPLASM of the body of a NEURON and extending from one DENDRITE into another or into the AXON.Amyloid beta-Peptides: Peptides generated from AMYLOID BETA-PEPTIDES PRECURSOR. An amyloid fibrillar form of these peptides is the major component of amyloid plaques found in individuals with Alzheimer's disease and in aged individuals with trisomy 21 (DOWN SYNDROME). The peptide is found predominantly in the nervous system, but there have been reports of its presence in non-neural tissue.Neurosciences: The scientific disciplines concerned with the embryology, anatomy, physiology, biochemistry, pharmacology, etc., of the nervous system.Tachycardia, Ventricular: An abnormally rapid ventricular rhythm usually in excess of 150 beats per minute. It is generated within the ventricle below the BUNDLE OF HIS, either as autonomic impulse formation or reentrant impulse conduction. Depending on the etiology, onset of ventricular tachycardia can be paroxysmal (sudden) or nonparoxysmal, its wide QRS complexes can be uniform or polymorphic, and the ventricular beating may be independent of the atrial beating (AV dissociation).Catecholamines: A general class of ortho-dihydroxyphenylalkylamines derived from tyrosine.Valsalva Maneuver: Forced expiratory effort against a closed GLOTTIS.Tachycardia: Abnormally rapid heartbeat, usually with a HEART RATE above 100 beats per minute for adults. Tachycardia accompanied by disturbance in the cardiac depolarization (cardiac arrhythmia) is called tachyarrhythmia.Sinus of Valsalva: The dilatation of the aortic wall behind each of the cusps of the aortic valve.Adenosine Deaminase: An enzyme that catalyzes the hydrolysis of ADENOSINE to INOSINE with the elimination of AMMONIA.Electrocardiography: Recording of the moment-to-moment electromotive forces of the HEART as projected onto various sites on the body's surface, delineated as a scalar function of time. The recording is monitored by a tracing on slow moving chart paper or by observing it on a cardioscope, which is a CATHODE RAY TUBE DISPLAY.World War I: Global conflict primarily fought on European continent, that occurred between 1914 and 1918.Famous PersonsPeriodicals as Topic: A publication issued at stated, more or less regular, intervals.VermontNew HampshireJournal Impact Factor: A quantitative measure of the frequency on average with which articles in a journal have been cited in a given period of time.Questionnaires: Predetermined sets of questions used to collect data - clinical data, social status, occupational group, etc. The term is often applied to a self-completed survey instrument.Internet: A loose confederation of computer communication networks around the world. The networks that make up the Internet are connected through several backbone networks. The Internet grew out of the US Government ARPAnet project and was designed to facilitate information exchange.Publishing: "The business or profession of the commercial production and issuance of literature" (Webster's 3d). It includes the publisher, publication processes, editing and editors. Production may be by conventional printing methods or by electronic publishing.Bibliometrics: The use of statistical methods in the analysis of a body of literature to reveal the historical development of subject fields and patterns of authorship, publication, and use. Formerly called statistical bibliography. (from The ALA Glossary of Library and Information Science, 1983)Nootropic Agents: Drugs used to specifically facilitate learning or memory, particularly to prevent the cognitive deficits associated with dementias. These drugs act by a variety of mechanisms. While no potent nootropic drugs have yet been accepted for general use, several are being actively investigated.Piracetam: A compound suggested to be both a nootropic and a neuroprotective agent.Pyrrolidinones: A group of compounds that are derivatives of oxo-pyrrolidines. A member of this group is 2-oxo pyrrolidine, which is an intermediate in the manufacture of polyvinylpyrrolidone. (From Merck Index, 11th ed)Central Nervous System Diseases: Diseases of any component of the brain (including the cerebral hemispheres, diencephalon, brain stem, and cerebellum) or the spinal cord.Vinca Alkaloids: A group of indole-indoline dimers which are ALKALOIDS obtained from the VINCA genus of plants. They inhibit polymerization of TUBULIN into MICROTUBULES thus blocking spindle formation and arresting cells in METAPHASE. They are some of the most useful ANTINEOPLASTIC AGENTS.HandwritingBacopa: A plant genus of the family Plantaginaceae. Members contain bacopaside, bacopasaponins and other dammarane type jujubogenins.Mescaline: Hallucinogenic alkaloid isolated from the flowering heads (peyote) of Lophophora (formerly Anhalonium) williamsii, a Mexican cactus used in Indian religious rites and as an experimental psychotomimetic. Among its cellular effects are agonist actions at some types of serotonin receptors. It has no accepted therapeutic uses although it is legal for religious use by members of the Native American Church.Neuroprotective Agents: Drugs intended to prevent damage to the brain or spinal cord from ischemia, stroke, convulsions, or trauma. Some must be administered before the event, but others may be effective for some time after. They act by a variety of mechanisms, but often directly or indirectly minimize the damage produced by endogenous excitatory amino acids.Epilepsies, Myoclonic: A clinically diverse group of epilepsy syndromes characterized either by myoclonic seizures or by myoclonus in association with other seizure types. Myoclonic epilepsy syndromes are divided into three subtypes based on etiology: familial, cryptogenic, and symptomatic (i.e., occurring secondary to known disease processes such as infections, hypoxic-ischemic injuries, trauma, etc.).Naphthoquinones: Naphthalene rings which contain two ketone moieties in any position. They can be substituted in any position except at the ketone groups.Butylated Hydroxytoluene: A di-tert-butyl PHENOL with antioxidant properties.Lipoxygenase Inhibitors: Compounds that bind to and inhibit that enzymatic activity of LIPOXYGENASES. Included under this category are inhibitors that are specific for lipoxygenase subtypes and act to reduce the production of LEUKOTRIENES.Phenols: Benzene derivatives that include one or more hydroxyl groups attached to the ring structure.Lipoxygenase: An enzyme of the oxidoreductase class primarily found in PLANTS. It catalyzes reactions between linoleate and other fatty acids and oxygen to form hydroperoxy-fatty acid derivatives.Vitamin K 3: A synthetic naphthoquinone without the isoprenoid side chain and biological activity, but can be converted to active vitamin K2, menaquinone, after alkylation in vivo.Fenretinide: A synthetic retinoid that is used orally as a chemopreventive against prostate cancer and in women at risk of developing contralateral breast cancer. It is also effective as an antineoplastic agent.GermanyArachidonate 5-Lipoxygenase: An enzyme that catalyzes the oxidation of arachidonic acid to yield 5-hydroperoxyarachidonate (5-HPETE) which is rapidly converted by a peroxidase to 5-hydroxy-6,8,11,14-eicosatetraenoate (5-HETE). The 5-hydroperoxides are preferentially formed in leukocytes.Plumbaginaceae: A plant family of the order Plumbaginales, subclass Caryophyllidae, class Magnoliopsida of shrubs and herbs. Some members contain ANTHOCYANINS and naphthaquinones.Brain Ischemia: Localized reduction of blood flow to brain tissue due to arterial obstruction or systemic hypoperfusion. This frequently occurs in conjunction with brain hypoxia (HYPOXIA, BRAIN). Prolonged ischemia is associated with BRAIN INFARCTION.Receptor, Adenosine A2A: A subclass of adenosine A2 receptors found in LEUKOCYTES, the SPLEEN, the THYMUS and a variety of other tissues. It is generally considered to be a receptor for ADENOSINE that couples to the GS, STIMULATORY G-PROTEIN.Disease Models, Animal: Naturally occurring or experimentally induced animal diseases with pathological processes sufficiently similar to those of human diseases. They are used as study models for human diseases.Pregnatrienes: Pregnane derivatives containing three double bonds in the ring structures.Xenon: A noble gas with the atomic symbol Xe, atomic number 54, and atomic weight 131.30. It is found in the earth's atmosphere and has been used as an anesthetic.Rats, Sprague-Dawley: A strain of albino rat used widely for experimental purposes because of its calmness and ease of handling. It was developed by the Sprague-Dawley Animal Company.Lymphoma, Follicular: Malignant lymphoma in which the lymphomatous cells are clustered into identifiable nodules within the LYMPH NODES. The nodules resemble to some extent the GERMINAL CENTER of lymph node follicles and most likely represent neoplastic proliferation of lymph node-derived follicular center B-LYMPHOCYTES.Yttrium Radioisotopes: Unstable isotopes of yttrium that decay or disintegrate emitting radiation. Y atoms with atomic weights 82-88 and 90-96 are radioactive yttrium isotopes.Lymphoma, Non-Hodgkin: Any of a group of malignant tumors of lymphoid tissue that differ from HODGKIN DISEASE, being more heterogeneous with respect to malignant cell lineage, clinical course, prognosis, and therapy. The only common feature among these tumors is the absence of giant REED-STERNBERG CELLS, a characteristic of Hodgkin's disease.Antibodies, Monoclonal, Murine-Derived: Antibodies obtained from a single clone of cells grown in mice or rats.Radioimmunotherapy: Radiotherapy where cytotoxic radionuclides are linked to antibodies in order to deliver toxins directly to tumor targets. Therapy with targeted radiation rather than antibody-targeted toxins (IMMUNOTOXINS) has the advantage that adjacent tumor cells, which lack the appropriate antigenic determinants, can be destroyed by radiation cross-fire. Radioimmunotherapy is sometimes called targeted radiotherapy, but this latter term can also refer to radionuclides linked to non-immune molecules (see RADIOTHERAPY).Antineoplastic Combined Chemotherapy Protocols: The use of two or more chemicals simultaneously or sequentially in the drug therapy of neoplasms. The drugs need not be in the same dosage form.Disease-Free Survival: Period after successful treatment in which there is no appearance of the symptoms or effects of the disease.Treatment Outcome: Evaluation undertaken to assess the results or consequences of management and procedures used in combating disease in order to determine the efficacy, effectiveness, safety, and practicability of these interventions in individual cases or series.Antibodies, Monoclonal: Antibodies produced by a single clone of cells.Prednisone: A synthetic anti-inflammatory glucocorticoid derived from CORTISONE. It is biologically inert and converted to PREDNISOLONE in the liver.
(1/174) Contribution of adenosine to the depression of sympathetically evoked vasoconstriction induced by systemic hypoxia in the rat.

Previous studies have shown that systemic hypoxia evokes vasodilatation in skeletal muscle that is mediated mainly by adenosine acting on A1 receptors, and that the vasoconstrictor effects of sympathetic nerve activity are depressed during hypoxia. The aim of the present study was to investigate the role of adenosine in this depression. In anaesthetised rats, increases in femoral vascular resistance (FVR) evoked by stimulation of the lumbar sympathetic chain with bursts of impulses at 40 or 20 Hz were greater than those evoked by continuous stimulation at 2 Hz with the same number of impulses (120) over 1 min. All of these responses were substantially reduced by infusion of adenosine or by graded systemic hypoxia (breathing 12, 10 or 8 % O2), increases in FVR evoked by continuous stimulation at 2 Hz being most vulnerable. Blockade of A1 receptors ameliorated the depression caused by adenosine infusion of the increase in FVR evoked by 2 Hz only and did not ameliorate the depression caused by 8 % O2 of increases in FVR evoked by any pattern of sympathetic stimulation. A2A receptor blockade accentuated hypoxia-induced depression of the increase in FVR evoked by burst stimulation at 40 Hz, but had no other effect. Neither A1 nor A2A receptor blockade affected the depression caused by hypoxia (8 % O2) of the FVR increase evoked by noradrenaline infusion. These results indicate that endogenously released adenosine is not responsible for the depression of sympathetically evoked muscle vasoconstriction caused by systemic hypoxia; adenosine may exert a presynaptic facilitatory influence on the vasoconstrictor responses evoked by bursts at high frequency.  (+info)

(2/174) Ischaemic tolerance in aged mouse myocardium: the role of adenosine and effects of A1 adenosine receptor overexpression.

The genesis of the ischaemia intolerant phenotype in aged myocardium is poorly understood. We tested the hypothesis that impaired adenosine-mediated protection contributes to ischaemic intolerance, and examined whether this is countered by A1 adenosine receptor (A1AR) overexpression. Responses to 20 min ischaemia and 45 min reperfusion were assessed in perfused hearts from young (2-4 months) and moderately aged (16-18 months) mice. Post-ischaemic contractility was impaired by ageing with elevated ventricular diastolic (32 +/- 2 vs. 18 +/- 2 mmHg in young) and reduced developed (37 +/- 3 vs. 83 +/- 6 mmHg in young) pressures. Lactate dehydrogenase (LDH) loss was exaggerated (27 +/- 2 vs. 16 +/- 2 IU g-1 in young) whereas the incidence of tachyarrhythmias was similar in young (15 +/- 1 %) and aged hearts (16 +/- 1 %). Functional analysis confirmed equipotent effects of 50 micro M adenosine at A1 and A2 receptors in young and aged hearts. Nonetheless, while 50 micro M adenosine improved diastolic (5 +/- 1 mmHg) and developed pressures (134 +/- 7 mmHg) and LDH loss (6 +/- 2 IU g-1) in young hearts, it did not alter these variables in the aged group. Adenosine did attenuate arrhythmogenesis for both ages (to ~10 %). In contrast to adenosine, 50 micro M diazoxide reduced ischaemic damage and arrhythmogenesis for both ages. Contractile and anti-necrotic effects of adenosine were limited by 100 micro M 5-hydroxydecanoate (5-HD) and 3 micro M chelerythrine. Anti-arrhythmic effects were limited by 5-HD but not chelerythrine. Non-selective (100 micro M 8-sulfophenyltheophylline) and A1-selective (150 nM 8-cyclopentyl-1,3-dipropylxanthine) adenosine receptor antagonism impaired ischaemic tolerance in young but not aged hearts. Quantitative real-time PCR and radioligand analysis indicated that impaired protection is unrelated to changes in A1AR mRNA transcription, or receptor density (~8 fmol mg-1 protein in both age groups). However, A1AR overexpression improved tolerance for both ages, restoring adenosine-mediated protection. These data reveal impaired protection via exogenous and endogenous adenosine contributes to ischaemic intolerance with ageing. This is independent of A1AR expression, and involves ineffective activation of a 5-HD-/diazoxide-sensitive process. The effects of A1AR overexpression indicate that the age-related failure in signalling can be overcome.  (+info)

(3/174) Alteration of the purinergic modulation of enteric neurotransmission in the mouse ileum during chronic intestinal inflammation.

1. The effect of chronic intestinal inflammation on the purinergic modulation of cholinergic neurotransmission was studied in the mouse ileum. Chronic intestinal inflammation was induced by infection of mice with the parasite Schistosoma mansoni during 16 weeks. 2. S. mansoni infection induced a chronic inflammatory response in the small intestine, which was characterised by intestinal granuloma formation, increased intestinal wall thickness, blunted mucosal villi and an enhanced activity of myeloperoxidase. 3. In control ileum and in chronically inflamed ileum, electrical field stimulation (EFS) of longitudinal muscle strips induced frequency-dependent contractions that were abolished by tetrodotoxin (TTX) and atropine. Carbachol induced dose-dependent contractions that were not affected by TTX but abolished by atropine. 4. In control ileum, adenosine and ATP dose-dependently inhibited the contractions to EFS. Theophylline and 8-phenyltheophylline, P(1) and A(1) receptor antagonists respectively, prevented this inhibitory effect of adenosine and ATP. PPADS, DMPX and MRS 1220, antagonists of P(2), A(2) and A(3) receptors, respectively, did not prevent this inhibitory effect of adenosine and ATP. Adenosine and ATP did not affect the contractions to carbachol. 5. The inhibitory effect of adenosine and ATP on contractions to EFS in control ileum was mimicked by the stable adenosine analogue methyladenosine and by the A(1)-receptor agonist N(6)-cyclohexyladenosine, but not by the A3 receptor agonist 2-Cl IB-MECA or by the ATP analogues alphabeta-methylene-ATP and ADPbetaS. The inhibitory effect of adenosine on contractions to EFS was lost after prolonged (90 min) treatment of control ileum with methyladenosine (100 micro M). 6. In chronically inflamed ileum, adenosine, methyladenosine, N(6)-cyclohexyladenosine and ATP all failed to inhibit the cholinergic nerve-mediated contractions to EFS. Also theophylline, 8-phenyltheophylline, PPADS, DMPX and MRS 1220 had no effect on the contractions to EFS and carbachol. The loss of effect of adenosine and ATP was still evident after 52 weeks of infection. 7. These results indicate that in physiological conditions neuronal adenosine A(1) receptors modulate cholinergic nerve activity in the mouse ileum. However, during chronic intestinal inflammation, this purinergic modulation of cholinergic nerve activity is impaired. This suggests that chronic intestinal inflammation leads to a dysfunction of specific neuronal regulatory mechanisms in the enteric nervous system.  (+info)

(4/174) Diadenosine-5-phosphate exerts A1-receptor-mediated proarrhythmic effects in rabbit atrial myocardium.

(1) Diadenosine polyphosphates have been described to be present in the myocardium and exert purinergic- and nonreceptor-mediated effects. Since the electrophysiological properties of atrial myocardium are effectively regulated by A(1) receptors, we investigated the effect of diadenosine pentaphosphate (Ap(5)A) in rabbit myocardium. (2) Parameters of supraventricular electrophysiology and atrial vulnerability were measured in Langendorff-perfused rabbit hearts. Muscarinic potassium current (I(K(ACh/Ado))) and ATP-sensitive potassium current (I(K(ATP))) were measured by using the whole-cell voltage clamp method. (3) Ap(5)A prolonged the cycle length of spontaneously beating Langendorff perfused hearts from 225+/-14 (control) to 1823+/-400 ms (Ap(5)A 50 micro M; n=6; P<0.05). This effect was paralleled by higher degree of atrio-ventricular block. Atrial effective refractory period (AERP) in control hearts was 84+/-14 ms (n=6). Ap(5)A>/=1 micro M reduced AERP (100 micro M, 58+/-11 ms; n=6). (4) Extrastimuli delivered to hearts perfused with Ap(5)A- or adenosine (>/= micro M)-induced atrial fibrillation, the incidence of which correlated to the concentration added to the perfusate. The selective A(1)-receptor antagonist CPX (20 micro M) inhibited the Ap(5)A- and adenosine-induced decrease of AERP. Atrial fibrillation was no longer observed in the presence of CPX. (5) The described Ap(5)A-induced effects in the multicellular preparation were enhanced by dipyridamole (10 micro M), which is a cellular adenosine uptake inhibitor. Dipyridamole-induced enhancement was inhibited by CPX. (6) Ap(5)A (+info)

(5/174) Comparison of effects of MgCl2 and Gpp(NH)p on antagonist and agonist radioligand binding to adenosine A1 receptors.

AIM: To investigate modulation of antagonist and agonist binding to adenosine A1 receptors by MgCl2 and 5 -guanylimidodiphosphate (Gpp(NH)p) using rat brain membranes and the A1 antagonist [3H]-8-cyclopentyl-1,3-dipropylxanthine ([3H]DPCPX) and the A1 agonist [3H]-2-chloro-N6-cyclopentyladenosine ([3H]CCPA). METHODS: Parallel saturation and inhibition studies were performed using well-characterised radioligand binding assays and a Brandel Cell Harvester. RESULTS: MgCl2 produced a concentration-dependent decrease (44%), whereas Gpp(NH)p increased [3H]DPCPX binding (19%). In [3H]DPCPX competition studies, agonist affinity was 1.5-14.6-fold higher and 4.6-10-fold lower in the presence of 10 mmol/L MgCl2 and 10 micromol/L Gpp(NH)p respectively; antagonist affinity was unaffected. The decrease in agonist affinity with increasing Gpp(NH)p concentrations was due to a reduction in the proportion of binding to the high affinity receptor state. In contrast to [3H]DPCPX, MgCl2 produced a concentration-dependent increase (72%) and Gpp(NH)p a decrease (85%) in [3H]CCPA binding. Using [3H]CCPA, agonist affinities were 5-17-fold higher than those for [3H]DPCPX, consistent with binding only to the high affinity receptor state. Agonist affinity was 1.3-10.5-fold higher and 2.4-4.7-fold lower on adding MgCl2 or Gpp(NH)p respectively; antagonist affinities were as for [3H]DPCPX. CONCLUSION: The inconsistencies surrounding the effects of MgCl2 and guanine nucleotides on radioligand binding to adenosine A1 receptors were systematically examined. The effects of MgCl2 and Gpp(NH)p on agonist binding to A1 receptors are consistent with their roles in stimulating GTP-hydrolysis at the G-protein alpha-subunit and in blocking formation of the high affinity agonist-receptor-G protein complex.  (+info)

(6/174) An orally active adenosine A1 receptor antagonist, FK838, increases renal excretion and maintains glomerular filtration rate in furosemide-resistant rats.

1. Loop and thiazide diuretics are common therapeutic agents for the treatment of sodium retention and oedema. However, resistance to diuretics and decreases in renal function can develop during diuretic therapy. Adenosine causes renal vasoconstriction, sodium reabsorption, and participates in the tubuloglomerular feedback mechanism for the regulation of glomerular filtration rate. 2. We tested the hypothesis that the selective adenosine A(1) receptor antagonist FK838 is orally active and causes diuresis and natriuresis, but maintains glomerular filtration rate in normal rats or in rats with furosemide resistance. 3. In normal male Sprague - Dawley rats, FK838 dose-dependently increased urine flow and sodium and chloride excretion while sparing potassium. In combination with furosemide, FK838 enhanced the diuretic and natriuretic actions of furosemide to the same extent as hydrochlorothiazide and did not increase the potassium loss in normal rats. In furosemide-resistant rats, FK838 increased urine flow and electrolyte excretion to a greater extent than hydrochlorothiazide. In addition, hydrochlorothiazide significantly decreased glomerular filtration rate, whereas FK838 maintained glomerular filtration rate in furosemide-resistant rats. 4. This study shows that the adenosine A(1) receptor antagonist FK838 is orally active and causes potent diuresis and natriuresis and maintains glomerular filtration rate in normal or furosemide-resistant rats. Adenosine A(1) receptor antagonists may be novel therapeutics for the treatment of oedema in normal or otherwise diuretic-resistant patients.  (+info)

(7/174) Brief, repeated, oxygen-glucose deprivation episodes protect neurotransmission from a longer ischemic episode in the in vitro hippocampus: role of adenosine receptors.

1. Ischemic preconditioning in the brain consists of reducing the sensitivity of neuronal tissue to further, more severe, ischemic insults. We recorded field epsps (fepsps) extracellularly from hippocampal slices to develop a model of in vitro ischemic preconditioning and to evaluate the role of A1, A2A and A3 adenosine receptors in this phenomenon. 2. The application of an ischemic insult, obtained by glucose and oxygen deprivation for 7 min, produced an irreversible depression of synaptic transmission. Ischemic preconditioning was induced by four ischemic insults (2 min each) separated by 13 min of normoxic conditions. After 30 min, an ischemic insult of 7 min was applied. This protocol substantially protected the tissue from the irreversible depression of synaptic activity. 3. The selective adenosine A1 receptor antagonist, 8-cyclopentyl-1,3-dipropylxanthine (DPCPX, 100 nm), completely prevented the protective effect of preconditioning. The selective adenosine A2A receptor antagonist 4-(2-[7-amino-2-(2-furyl)[1,2,4]triazolo[2,3-a][1,3,5]triazin-5-ylamino]ethyl)phe nol (ZM 241385, 100 nm) did not modify the magnitude of fepsp recovery compared to control slices. The selective A3 adenosine receptor antagonists, 3-propyl-6-ethyl-5[ethyl(thio)carbonyl]-2-phenyl-4-propyl-3-pyridinecarboxylate (MRS 1523, 100 nm) significantly improved the recovery of fepsps after 7 min of ischemia. 4. Our results show that in vitro ischemic preconditioning allows CA1 hippocampal neurons to become resistant to prolonged exposure to ischemia. Adenosine, by stimulating A1 receptors, plays a crucial role in eliciting the cell mechanisms underlying preconditioning; A2A receptors are not involved in this phenomenon, whereas A3 receptor activation is harmful to ischemic preconditioning.  (+info)

(8/174) Involvement of adenosine A1 and A2A receptors in the adenosinergic modulation of the discriminative-stimulus effects of cocaine and methamphetamine in rats.

Adenosine, by acting on adenosine A1 and A2A receptors, is known to antagonistically modulate dopaminergic neurotransmission. We have recently reported that nonselective adenosine receptor antagonists (caffeine and 3,7-dimethyl-1-propargylxanthine) can partially substitute for the discriminative-stimulus effects of methamphetamine. In the present study, by using more selective compounds, we investigated the involvement of A1 and A2A receptors in the adenosinergic modulation of the discriminative-stimulus effects of both cocaine and methamphetamine. The effects of the A1 receptor agonist N6-cyclopentyladenosine (CPA; 0.01-0.1 mg/kg) and antagonist 8-cyclopentyl-1,3-dimethylxanthine (CPT; 1.3-23.7 mg/kg) and the A2A receptor agonist 2-p-(2-carboxyethyl)phenethylamino-5'-N-ethylcarboxamidoadenosine hydrochloride (CGS 21680; 0.03-0.18 mg/kg) and antagonist 3-(3-hydroxypropyl)-8-(3-methoxystyryl)-7-methyl-1-propargylxanthin phosphate disodium salt (MSX-3; 1-56 mg/kg) were evaluated in rats trained to discriminate either 1 mg/kg methamphetamine or 10 mg/kg cocaine from saline under a fixed-ratio 10 schedule of food presentation. The A1 and A2A receptor antagonists (CPT and MSX-3) both produced high levels of drug-lever selection when substituted for either methamphetamine or cocaine and significantly shifted dose-response curves of both psychostimulants to the left. Unexpectedly, the A2A receptor agonist CGS 21680 also produced drug-appropriate responding (although at lower levels) when substituted for the cocaine-training stimulus, and both CGS 21680 and the A1 receptor agonist CPA significantly shifted the cocaine dose-response curve to the left. In contrast, both agonists did not produce significant levels of drug-lever selection when substituted for the methamphetamine-training stimulus and failed to shift the methamphetamine dose-response curve. Therefore, adenosine A1 and A2A receptors appear to play important but differential roles in the modulation of the discriminative-stimulus effects of methamphetamine and cocaine.  (+info)

*  Adenosine receptor
He W, Wilder T, Cronstein BN (2013) Rolofylline, an adenosine A1 receptor antagonist, inhibits osteoclast differentiation as an ... The adenosine receptors (or P1 receptors) are a class of purinergic G protein-coupled receptors with adenosine as endogenous ... The adenosine A1 receptor has been found to be ubiquitous throughout the entire body. This receptor has an inhibitory function ... Adenosine receptors play a key role in the homeostasis of bone. The A1 receptor has been shown to stimulate osteoclast ...
*  Adenosine A2A receptor
"Time and sex-dependent effects of an adenosine A2A/A1 receptor antagonist on motivation to self-administer cocaine in rats". ... Older research on adenosine receptor function, and non-selective adenosine receptor antagonists such as aminophylline, focused ... As a result, Adenosine receptor A2A decreases activity in the Dopamine D2 receptors. The adenosine A2A receptor has also been ... "Chromosomal mapping of A1 and A2 adenosine receptors, VIP receptor, and a new subtype of serotonin receptor". Genomics. 11 (1 ...
*  Adenosine A3 receptor
... a novel specific adenosine A(3) receptor antagonist with adenosine A(3) receptor agonists both in vitro and in vivo". Eur. J. ... 1999). "Cardiac myocytes rendered ischemia resistant by expressing the human adenosine A1 or A3 receptor". FASEB J. 12 (15): ... a novel ligand that demonstrates both adenosine A(2A) receptor agonist and adenosine A(3) receptor antagonist activity". ... is an adenosine receptor, but also denotes the human gene encoding it. Adenosine A3 receptors are G protein-coupled receptors ...
*  Adenosine A1 receptor
... an adenosine A1-receptor antagonist,on diuresis and renal function in patients with acute decompensated heart failure and renal ... The adenosine A1 receptor is one member of the adenosine receptor group of G protein-coupled receptors with adenosine as ... The adenosine A1 receptor has been found to be ubiquitous throughout the entire body. Activation of the adenosine A1 receptor ... "Adenosine Receptors: A1". IUPHAR Database of Receptors and Ion Channels. International Union of Basic and Clinical Pharmacology ...
*  Dipropylcyclopentylxanthine
... is a drug which acts as a potent and selective antagonist for the adenosine A1 receptor. It has high selectivity for A1 over ... "Potent adenosine receptor antagonists that are selective for the A1 receptor subtype". Molecular Pharmacology. 31 (3): 247-52. ... Chwalczuk K, Rubaj A, Swiader M, Czuczwar SJ (2008). "[Influence of the antagonist of adenosine A1 receptors, 8-cyclopentyl-1 , ... a selective high affinity antagonist radioligand for A1 adenosine receptors". Naunyn-Schmiedeberg's Archives of Pharmacology. ...
*  Rolofylline
... (KW-3902) is an experimental diuretic which acts as a selective adenosine A1 receptor antagonist. It was discovered ... an adenosine A1-receptor antagonist, on diuresis and renal function in patients with acute decompensated heart failure and ... dose-finding study of the adenosine A1 receptor antagonist rolofylline in patients with acute heart failure and renal ...
*  Bamifylline
... is a drug of the xanthine chemical class which acts as a selective adenosine A1 receptor antagonist. Theophylline ... "Effects of A1 adenosine receptor blockade by bamiphylline on ischaemic preconditioning during coronary angioplasty" (PDF). ...
*  Cardiorenal syndrome
Givertz, M. M.; Massie B. M.; Fields T. K.; Pearson L. L. (2007). "The effects of KW-3902 an adenosine A1-receptor antagonist, ... It was found that an adenosine A1-receptor antagonist called KW-3902 was able to improve kidney function in CRS patients. ... Vasopressin antagonists Tolvaptan showed to have no benefit. It is also a very costly drug. Adenosine antagonists Adenosine is ...
*  Diprophylline
Schwabe, U; Ukena, D; Lohse, MJ (September 1985). "Xanthine Derivatives as Antagonists at A1 and A2 Adenosine Receptors". ... It acts as an adenosine receptor antagonist and phosphodiesterase inhibitor. Xanthine "International Non-Proprietary Names. ...
*  ATL-444
... is a drug which acts as a potent and reasonably selective antagonist for the adenosine receptors A1 and A2A. It has ... "Time and sex-dependent effects of an adenosine A2A/A1 receptor antagonist on motivation to self-administer cocaine in rats". ... been used to study the role of the adenosine receptor system in the reinforcing action of cocaine. CGS-15943 Doyle, S. E.; ...
*  CGS-15943
"Comparison of the behavioural effects of an adenosine A1/A2-receptor antagonist, CGS 15943A, and an A1-selective antagonist, ... CGS-15943 is a drug which acts as a potent and reasonably selective antagonist for the adenosine receptors A1 and A2A, having a ... Ki of 3.3nM at A2A and 21nM at A1. It was one of the first adenosine receptor antagonists discovered that is not a xanthine ... Holtzman SG (1991). "CGS 15943, a nonxanthine adenosine receptor antagonist: effects on locomotor activity of nontolerant and ...
*  Cartazolate
... activity as antagonists of A1- and A2-adenosine receptors". Biochemical Pharmacology. 37 (4): 655-64. doi:10.1016/0006-2952(88) ... It is also known to act as an adenosine antagonist at the A1 and A2 subtypes and as a phosphodiesterase inhibitor. Cartazolate ... "Perturbation of benzodiazepine receptor binding by pyrazolopyridines involves picrotoxinin/barbiturate receptor sites". Journal ... O'Brien, Robert (1986). Receptor binding in drug research. New York: Dekker. p. 519. ISBN 0-8247-7548-1. US Patent 3966746 ...
*  8-Phenyltheophylline
... is a drug derived from the xanthine family which acts as a potent and selective antagonist for the adenosine receptors A1 and ... Howell LL; Morse WH; Spealman RD (September 1990). "Respiratory effects of xanthines and adenosine analogs in rhesus monkeys". ... Spealman RD (1988). "Psychomotor stimulant effects of methylxanthines in squirrel monkeys: relation to adenosine antagonism". ...
*  SCH-58261
Popoli P, Reggio R, Pèzzola A, Fuxe K, Ferré S (July 1998). "Adenosine A1 and A2A receptor antagonists stimulate motor activity ... SCH-58261 is a drug which acts as a potent and selective antagonist for the adenosine receptor A2A, with more than 50x ... Kuzmin A, Johansson B, Gimenez L, Ogren SO, Fredholm BB (February 2006). "Combination of adenosine A1 and A2A receptor blocking ... "The non-xanthine heterocyclic compound SCH 58261 is a new potent and selective A2a adenosine receptor antagonist". The Journal ...
*  Caffeine
... is an antagonist at all four adenosine receptor subtypes (A1, A2A, A2B, and A3), although with varying potencies. The ... specifically the A1-D1 receptor heterodimer (this is a receptor complex with 1 adenosine A1 receptor and 1 dopamine D1 receptor ... a receptor complex composed of 1 adenosine A1 receptor and 1 adenosine A2A receptor) in the axon terminal of glutamate neurons ... this is a receptor complex with 2 adenosine A2A receptors and 2 dopamine D2 receptors). The A2A-D2 receptor heterotetramer has ...
*  Caffeine-induced anxiety disorder
Caffeine acts as an antagonist of adenosine A1 and A2A receptors. Adenosine is a normal neuromodulator that activates adenosine ... A1 receptors are paired with the G-proteins of Gi-1, Gi-2, Gi-3, Go1, and Go2. The g-proteins of A1 receptors continue to ... The actions of A1 and A2A receptors oppose each other but are both inhibited by caffeine due to its function as an antagonist. ... Adenosine acts on A1 receptors to decrease opening of N-type Ca2+ channels in some hippocampal neurons, and therefore decrease ...
*  Theophylline
... and reduces inflammation and innate immunity nonselective adenosine receptor antagonist, antagonizing A1, A2, and A3 receptors ... Daly JW, Jacobson KA, Ukena D (1987). "Adenosine receptors: development of selective agonists and antagonists". Prog Clin Biol ... asthma infant apnea Blocks the action of adenosine; an inhibitory neurotransmitter that induces sleep, contracts the smooth ...
*  Purinergic signalling
... leading to an accumulation of adenosine. On the other hand, the adenosine-receptor antagonist caffeine reverses the anti- ... The other three adenosine receptors are involved in bone formation. In Alzheimer's disease (AD), the expression of A1 and A2A ... In the airways of patients with asthma, the expression of adenosine receptors is upregulated. Adenosine receptors affect ... the expression of adenosine receptors on the neutrophil, and the affinity of these receptors for adenosine. Micromolar ...
*  Adenosine A2B receptor
2001). "Differential gene expression of adenosine A1, A2a, A2b, and A3 receptors in the human enteric nervous system". J. Comp ... Cacciari B, Pastorin G, Bolcato C, Spalluto G, Bacilieri M, Moro S (December 2005). "A2B adenosine receptor antagonists: recent ... The adenosine A2B receptor, also known as ADORA2B, is a G-protein coupled adenosine receptor, and also denotes the human ... "The A2b adenosine receptor mediates cAMP responses to adenosine receptor agonists in human intestinal epithelia". J. Biol. Chem ...
*  SCH-442,416
Brain adenosine A2A receptor occupancy by a novel A1/A2A receptor antagonist, ASP5854, in rhesus monkeys: relationship to ... SCH-442,416 is a highly selective adenosine A2a subtype receptor antagonist. It is widely used in its 11C radiolabelled form to ... Adenosine A2A receptors and depression. Neurology. 2003 Dec 9;61(11 Suppl 6):S82-7. PMID 14663017 Matsuya T, Takuma K, Sato K, ... In vivo imaging of adenosine A2A receptors in rat and primate brain using [11C]SCH442416. European Journal of Nuclear Medicine ...
*  8-Cyclopentyl-1,3-dimethylxanthine
... is a drug which acts as a potent and selective antagonist for the adenosine receptors, with some selectivity for the A1 ... "Involvement of adenosine A1 and A2A receptors in the motor effects of caffeine after its acute and chronic administration". ... relation to adenosine antagonism". Psychopharmacology. 95 (1): 19-24. doi:10.1007/bf00212759. PMID 3133696. Karcz-Kubicha M; ... receptor subtype, as well as a non-selective phosphodiesterase inhibitor. It has stimulant effects in animals with slightly ...
*  DMPX
... is a caffeine analog which displays affinity to A2 adenosine receptors, in contrast to the A1 subtype receptors. DMPX had 28× ... a potent and selective in vivo antagonist of adenosine analogs. Life Sci. 1988;43(21):1671-84. PMID 3193854. ...
*  PPADS
... and adenosine A1 receptors. PPADS tetrasodium salt, Santa Cruz Biotechnology Ziganshin, AU (December 1993). "PPADS selectively ... PPADS (pyridoxalphosphate-6-azophenyl-2',4'-disulfonic acid) is a selective purinergic P2X antagonist. It is able to block ... It appears to be relatively selective for P2X receptors, having no appreciable activity at α1 adrenergic, muscarinic M2 and M3 ... Lambrecht, G. (1992). "PPADS, a novel functionally selective antagonist of P2 purinoreceptor mediated responses". European ...
*  Acupuncture
The anti-nociceptive effect of acupuncture may be mediated by the adenosine A1 receptor. A 2014 review in Nature Reviews Cancer ... and that it is possible to inhibit acupuncture's analgesic effects with the opioid antagonist naloxone. Mechanical deformation ... which then triggered nearby A1 receptors "caused more tissue damage and inflammation relative to the size of the animal in mice ... such studies unnecessarily muddled a finding that local inflammation can result in the local release of adenosine with ...
*  Etazolate
It acts as a positive allosteric modulator of the GABAA receptor at the barbiturate binding site, as an adenosine antagonist of ... the A1 and A2 subtypes, and as a phosphodiesterase inhibitor selective for the PDE4 isoform. It is currently in clinical trials ... ISBN 3-7643-1837-6. Williams M, Jarvis MF (February 1988). "Adenosine antagonists as potential therapeutic agents". ... Zezula J, Slany A, Sieghart W (April 1996). "Interaction of allosteric ligands with GABAA receptors containing one, two, or ...
*  Pre-Bötzinger complex
Adenosine modulates the preBötC output via activation of the A1 and A2A receptor subtypes. An adenosine A1 receptor agonist has ... most being selective agonists or antagonists to receptor subtypes on neurons in the vicinity. Since many of these neurons ... Effects of adenosine A1 receptor activation". BMC Neuroscience. 9: 95. doi:10.1186/1471-2202-9-95. PMC 2567986 . PMID 18826652 ... Another synthetic drug specific to the adenosine A2A receptor subtype is CGS-21680 that has been shown to cause apneas in 14- ...
*  Pharmacodynamics
... adenosine receptor antagonist, on the negative inotropic action of A(1) adenosine receptor full agonists in isolated guinea pig ... Dhalla AK, Shryock JC, Shreeniwas R, Belardinelli L (2003). "Pharmacology and therapeutic applications of A1 adenosine receptor ... Hormone receptors Neuromodulator receptors Neurotransmitter receptors General anesthetics were once thought to work by ... Upon drug binding, receptors can elicit their normal action (agonist), blocked action (antagonist), or even action opposite to ...
Effects of the Adenosine A1 Receptor Antagonist Rolofylline on Renal Function in Patients With Acute Heart Failure and Renal...  Effects of the Adenosine A1 Receptor Antagonist Rolofylline on Renal Function in Patients With Acute Heart Failure and Renal...
Effects of the Adenosine A1 Receptor Antagonist Rolofylline on Renal Function in Patients With Acute Heart Failure and Renal ... 2010) Rolofylline, an adenosine A1-receptor antagonist, in acute heart failure. N Engl J Med 363:1419-1428. ... 2007) The effect of KW-3902, an adenosine A1 receptor antagonist, on renal function and renal plasma flow in ambulatory ... 2007) The effects of KW-3902, an adenosine A1-receptor antagonist, on diuresis and renal function in patients with acute ...
more infohttp://www.onlinejacc.org/content/57/19/1899?ijkey=c7dcc08822203874414d7386c93119da15a724e6&keytype2=tf_ipsecsha
PDF] CVT-124, a novel adenosine A1 receptor antagonist with unique diuretic activity. - Semantic Scholar  PDF] CVT-124, a novel adenosine A1 receptor antagonist with unique diuretic activity. - Semantic Scholar
Administration of the selective adenosine A1 receptor antagonist, CVT-124, to conscious chronically instrumented rats resulted ... Adenosine A1 receptor antagonist blunts urinary potassium excretion, but not renal hemodynamic effects, induced by carbonic ... 1,3-Dipropyl-8-[2-(5,6-epoxy)norbornyl]xanthine, a potent, specific and selective A1 adenosine receptor antagonist in the ... CVT-124, a novel adenosine A1 receptor antagonist with unique diuretic activity.. @article{Gellai1998CVT124AN, title={CVT-124, ...
more infohttps://www.semanticscholar.org/paper/CVT-124%2C-a-novel-adenosine-A1-receptor-antagonist-Gellai-Schreiner/8b0e0ca99f57e2972eaa776bbad30de213609a4d
New pyrazolo[3,4-b]pyridones as selective A1 adenosine receptor antagonists: synthesis, biological evaluation and molecular...  New pyrazolo[3,4-b]pyridones as selective A1 adenosine receptor antagonists: synthesis, biological evaluation and molecular...
Binding affinities of the new compounds were determined for adenosine A, A and A receptors. Compounds and showed good affinity ... has been synthesized as potential A adenosine receptor (A AR) ligands. ... New pyrazolo[3,4-b]pyridones as selective A1 adenosine receptor antagonists: synthesis, biological evaluation and molecular ... New pyrazolo[3,4-b]pyridones as selective A1 adenosine receptor antagonists: synthesis, biological evaluation and molecular ...
more infohttps://pubs.rsc.org/en/Content/ArticleLanding/OB/2005/B502831K
Thermodynamics of full agonist, partial agonist, and antagonist binding to wild-type and mutant adenosine A1 receptors | Garvan...  Thermodynamics of full agonist, partial agonist, and antagonist binding to wild-type and mutant adenosine A1 receptors | Garvan...
... adenosine A1 receptors expressed on Chinese hamster ovary (CHO) cells, and to rat brain adenosine A1 receptors was undertaken. ... Thermodynamics of full agonist, partial agonist, and antagonist binding to wild-type and mutant adenosine A1 receptors. ... Thermodynamics of full agonist, partial agonist, and antagonist binding to wild-type and mutant adenosine A1 receptors ... Thermodynamics of full agonist, partial agonist, and antagonist binding to wild-type and mutant adenosine A1 receptors ...
more infohttps://www.garvan.org.au/research/publications/1161
Interactions of purified bovine brain A1-adenosine receptors with G-proteins. Reciprocal modulation of agonist and antagonist...  Interactions of purified bovine brain A1-adenosine receptors with G-proteins. Reciprocal modulation of agonist and antagonist...
Interactions of purified bovine brain A1-adenosine receptors with G-proteins. Reciprocal modulation of agonist and antagonist ... that the regulatory effect of G-proteins on antagonist binding to the A1-adenosine receptor can be reconstituted by using ... The bovine brain A1-adenosine receptor was purified 8000-fold by affinity chromatography on xanthine-amine-congener (XAC)- ... Interactions of purified bovine brain A1-adenosine receptors with G-proteins. Reciprocal modulation of agonist and antagonist ...
more infohttp://www.biochemj.org/content/275/3/651?ijkey=2315fd1b806ff30b6970ab77aeda8bbc35ec77ac&keytype2=tf_ipsecsha
A Comparison of the Antagonist Affinities for the Gi- and Gs-Coupled States of the Human Adenosine A1-Receptor | Journal of...  A Comparison of the Antagonist Affinities for the Gi- and Gs-Coupled States of the Human Adenosine A1-Receptor | Journal of...
... conformations of the adenosine A1-receptor in Chinese hamster ovary cells stably expressing the human adenosine A1-receptor and ... A Comparison of the Antagonist Affinities for the Gi- and Gs-Coupled States of the Human Adenosine A1-Receptor. Jillian G. ... A Comparison of the Antagonist Affinities for the Gi- and Gs-Coupled States of the Human Adenosine A1-Receptor. Jillian G. ... A Comparison of the Antagonist Affinities for the Gi- and Gs-Coupled States of the Human Adenosine A1-Receptor. Jillian G. ...
more infohttp://jpet.aspetjournals.org/content/320/1/218
Effects of the adenosine A1 receptor antagonist rolofylline on renal function in patients with acute heart failure and renal...  Effects of the adenosine A1 receptor antagonist rolofylline on renal function in patients with acute heart failure and renal...
Placebo-Controlled Randomized Study of the Selective Adenosine A1 Receptor Antagonist Rolofylline for Patients Hospitalized ... Effects of the adenosine A1 receptor antagonist rolofylline on renal function in patients with acute heart failure and renal ... Effects of the adenosine A1 receptor antagonist rolofylline on renal function in patients with acute heart failure and renal ... A Study of the Selective A1 Adenosine Receptor Antagonist KW-3902 for Patients Hospitalized With Acute HF and Volume Overload ...
more infohttps://scholars.duke.edu/display/pub744977
A Category Names List - Drug Information Portal - U.S. National Library of Medicine  A Category Names List - Drug Information Portal - U.S. National Library of Medicine
Adenosine A1 Receptor Antagonists (3) • Compounds that bind to and block the stimulation of ADENOSINE A1 RECEPTORS. MeSH ... Adenosine A2A Receptor Antagonists (0) see Adenosine A2 Receptor Antagonists. Adenosine A2B Receptor Agonists (0) see Adenosine ... Adenosine A2 Receptor Antagonists (8) • Compounds that selectively bind to and block the activation of ADENOSINE A2 RECEPTORS. ... Adenosine A3 Receptor Antagonists (1). Adenosine Deaminase Inhibitors (8) • Drugs that inhibit ADENOSINE DEAMINASE activity. ...
more infohttps://druginfo.nlm.nih.gov/drugportal/drug/categories
A Category Names List - Drug Information Portal - U.S. National Library of Medicine  A Category Names List - Drug Information Portal - U.S. National Library of Medicine
Adenosine A1 Receptor Antagonists (3) • Compounds that bind to and block the stimulation of ADENOSINE A1 RECEPTORS. MeSH ... Adenosine A2A Receptor Antagonists (0) see Adenosine A2 Receptor Antagonists. Adenosine A2B Receptor Agonists (0) see Adenosine ... Adenosine A2 Receptor Antagonists (8) • Compounds that selectively bind to and block the activation of ADENOSINE A2 RECEPTORS. ... Adenosine A3 Receptor Antagonists (1). Adenosine Deaminase Inhibitors (8) • Drugs that inhibit ADENOSINE DEAMINASE activity. ...
more infohttps://druginfo.nlm.nih.gov/drugportal/jsp/drugportal/drugNamesAndCategories.jsp
Frontiers | Tau Oligomers: Cytotoxicity, Propagation, and Mitochondrial Damage | Frontiers in Aging Neuroscience  Frontiers | Tau Oligomers: Cytotoxicity, Propagation, and Mitochondrial Damage | Frontiers in Aging Neuroscience
Dennissen, F. J., Anglada-Huguet, M., Sydow, A., Mandelkow, E., and Mandelkow, E. M. (2016). Adenosine A1 receptor antagonist ... blocking M1 and M3 receptors via receptor antagonists can prevent cytotoxic effects (Gómez-Ramos et al., 2008). ... Tau can interact with muscarinic receptors; more specifically, M1 and M3 receptors have approximately a 10-fold higher affinity ... Receptor-Mediated Endocytosis. Tau may be endocytosed, promoting an increase in intracellular calcium that results in neuronal ...
more infohttps://www.frontiersin.org/articles/10.3389/fnagi.2017.00083/full
Response of nonreentrant catecholamine-mediated ventricular tachycardia to endogenous adenosine and acetylcholine. Evidence for...  Response of nonreentrant catecholamine-mediated ventricular tachycardia to endogenous adenosine and acetylcholine. Evidence for...
VT recurred with the addition of aminophylline, a competitive adenosine A1-receptor antagonist. Edrophonium (10 mg i.v.), a ... The antiarrhythmic effects of exogenous adenosine and Valsalva on this form of VT may be due to receptor-mediated inhibition of ... It can be identified by termination of the tachycardia in response to activation of the adenosine A1 or muscarinic cholinergic ... Group 3 (n = 4): Adenosine and vagal maneuvers had no effect on catecholamine-mediated VT caused by automaticity in three of ...
more infohttp://circ.ahajournals.org/content/87/2/382
Hemodynamically, the kidney is at the heart of cardiorenal syndrome | Cleveland Clinic Journal of Medicine  Hemodynamically, the kidney is at the heart of cardiorenal syndrome | Cleveland Clinic Journal of Medicine
Rolofylline, an adenosine A1-receptor antagonist, in acute heart failure. N Engl J Med 2010; 363:1419-1428. ... Rolofylline, an adenosine A1-receptor antagonist, in acute heart failure. N Engl J Med 2010; 363:1419-1428. ... or renin-angiotensin system antagonist use or when P B is increased in the setting of elevated central venous pressure or ...
more infohttps://www.mdedge.com/ccjm/article/159386/cardiology/hemodynamically-kidney-heart-cardiorenal-syndrome
Relation of 24-hour urinary caffeine and caffeine metabolite excretions with self-reported consumption of coffee and other...  Relation of 24-hour urinary caffeine and caffeine metabolite excretions with self-reported consumption of coffee and other...
Natriuretic and diuretic actions of a highly selective adenosine A1 receptor antagonist. J Am Soc Nephrol. 1999;10(4):714-20. ... a family of nonspecific adenosine receptor antagonists with several physiological properties, including diuresis and ... Nomenclature and classification of adenosine receptors. Pharmacol Rev. 2001;53(4):527-52.PubMedGoogle Scholar. ... provides protection against dopaminergic cell death via stimulation of ryanodine receptor channels. Mol Pharmacol. 2008;74(4): ...
more infohttps://nutritionandmetabolism.biomedcentral.com/articles/10.1186/s12986-016-0144-4
Full text] Current treatments for acute heart failure: focus on serelaxin | RRCC  Full text] Current treatments for acute heart failure: focus on serelaxin | RRCC
Rolofylline, an adenosine A1-receptor antagonist, in acute heart failure. N Engl J Med. 2010;363(15):1419-1428. ... Among the adenosine A1 receptor blockers developed, rolofylline has the lowest specificity for the A1 receptor, with 32-fold ... known as the A1, A2a, A2b, and A3 receptors.43,44 In the kidney, adenosine activates the A1 receptor to cause vasoconstriction ... Effects of the adenosine A1 receptor antagonist rolofylline on renal function in patients with acute heart failure and renal ...
more infohttps://www.dovepress.com/current-treatments-for-acute-heart-failure-focus-on-serelaxin-peer-reviewed-fulltext-article-RRCC
JC1011 | Percutaneous Coronary Intervention | Cholesterol  JC1011 | Percutaneous Coronary Intervention | Cholesterol
Rolofylline is an adenosine A1-receptor antagonist that relieved dyspnea and reduced renal dysfunction in previous studies. In ... Rolofylline, an adenosine A1- receptor antagonist, in acute heart failure. N Engl J Med 2010 Oct 7; 363:1419. ... Celiprolol, a β1-adrenoceptor antagonist with partial β2-adrenoceptor agonist action, has been used for hypertension in various ... Despite the mechanistic appeal of targeting the adenosine pathway and the promising preliminary study results, rolofylline ...
more infohttps://www.scribd.com/document/96538149/JC1011
The AMEDEO Literature Guide  The AMEDEO Literature Guide
Nanoconjugate-bound adenosine A1 receptor antagonist enhances recovery of breathing following acute cervical spinal cord injury ... The GluN1/GluN2B NMDA receptor and metabotropic glutamate receptor 1 negative allosteric modulator has enhanced neuroprotection ... The toll-like receptor 2 agonist Pam3CSK4 is neuroprotective after spinal cord injury.. Exp Neurol. 2017 Apr 23. pii: S0014- ... Influence of Urothelial or Suburothelial Cholinergic Receptors on Bladder Reflexes in Chronic Spinal Cord Injured Cats.. Exp ...
more infohttp://amedeo.com/medicine/nsu/expneuro.htm
Kost C[au] - PubMed - NCBI  Kost C[au] - PubMed - NCBI
Adenosine A1 receptor antagonist blunts urinary potassium excretion, but not renal hemodynamic effects, induced by carbonic ... Muscarinic 2 receptors modulate cardiac proteasome function in a protein kinase G-dependent manner. ...
more infohttps://www.ncbi.nlm.nih.gov/pubmed?cmd=search&term=Kost+C%5Bau%5D&dispmax=50
Adenosine A1 receptor - Wikipedia  Adenosine A1 receptor - Wikipedia
... an adenosine A1-receptor antagonist,on diuresis and renal function in patients with acute decompensated heart failure and renal ... The adenosine A1 receptor is one member of the adenosine receptor group of G protein-coupled receptors with adenosine as ... The adenosine A1 receptor has been found to be ubiquitous throughout the entire body. Activation of the adenosine A1 receptor ... "Adenosine Receptors: A1". IUPHAR Database of Receptors and Ion Channels. International Union of Basic and Clinical Pharmacology ...
more infohttps://en.wikipedia.org/wiki/Adenosine_A1_receptor
Dipropylcyclopentylxanthine - Wikipedia  Dipropylcyclopentylxanthine - Wikipedia
... is a drug which acts as a potent and selective antagonist for the adenosine A1 receptor. It has high selectivity for A1 over ... "Potent adenosine receptor antagonists that are selective for the A1 receptor subtype". Molecular Pharmacology. 31 (3): 247-52. ... Chwalczuk K, Rubaj A, Swiader M, Czuczwar SJ (2008). "[Influence of the antagonist of adenosine A1 receptors, 8-cyclopentyl-1 , ... a selective high affinity antagonist radioligand for A1 adenosine receptors". Naunyn-Schmiedeberg's Archives of Pharmacology. ...
more infohttps://en.wikipedia.org/wiki/Dipropylcyclopentylxanthine
Piracetam and Piracetam-Like Drugs | SpringerLink  Piracetam and Piracetam-Like Drugs | SpringerLink
Administration of phosphodiesterase inhibitors and an adenosine A1 receptor antagonist induces phrenic nerve recovery in high ... receptor function via protein kinase C activation and reduces magnesium block of NMDA receptor. Mol Pharmacol 2007 Feb;71(2): ... Glutamate receptor dynamics in dendritic microdomains. Neuron 2008 May 22; 58(4): 472-97PubMedCrossRefGoogle Scholar ... Neugebauer V. Glutamate receptor ligands. Handb Exp Pharmacol 2007; 177: 217-49PubMedCrossRefGoogle Scholar ...
more infohttps://link.springer.com/article/10.2165%2F11319230-000000000-00000
  • Addition of a 120-fold molar excess of a purified bovine brain G-protein preparation (Go,i a mixture of Go and Gi, containing predominantly Go) decreases the Bmax of the binding of the antagonist radioligand [3H]XAC to the receptor. (biochemj.org)
  • A thermodynamic analysis of the binding of a full agonist (N6-cyclopentyladenosine), a partial agonist (8-butylamino-N6-cyclopentyladenosine) and an antagonist (8-cyclopentyltheophylline) to human wild-type and mutant (mutation of a threonine (Thr) to an alanine (Ala) residue at position 277) adenosine A1 receptors expressed on Chinese hamster ovary (CHO) cells, and to rat brain adenosine A1 receptors was undertaken. (garvan.org.au)
  • The D2Lh form may function as a classical post-synaptic receptor, i.e., transmit information (in either an excitatory or an inhibitory fashion) unless blocked by a receptor antagonist or a synthetic partial agonist. (wikipedia.org)
  • The antiarrhythmic effects of exogenous adenosine and Valsalva on this form of VT may be due to receptor-mediated inhibition of adenylate cyclase or to noncardiac receptor-mediated effects, i.e., exogenous adenosine may modulate VT through alterations in autonomic tone by activation of arterial chemoreceptors, and Valsalva has been shown to decrease venous return, resulting in a reduction in cardiac dimensions and myocardial stretch. (ahajournals.org)
  • It can be identified by termination of the tachycardia in response to activation of the adenosine A1 or muscarinic cholinergic receptor, which results in inhibition of adenylate cyclase. (ahajournals.org)
  • D2 receptor signaling may mediate protein kinase B, arrestin beta 2, and GSK-3 activity, and inhibition of these proteins results in stunting of the hyperlocomotion in amphetamine treated rats. (wikipedia.org)
  • Activation of the adenosine A1 receptor by an agonist causes binding of Gi1/2/3 or Go protein. (wikipedia.org)
  • Adenosine receptor activation and nociception. (semanticscholar.org)
  • It involves the activation of purinergic receptors in the cell and/or in nearby cells, thereby regulating cellular functions. (wikipedia.org)
  • During the blood clotting process, adenosine diphosphate (ADP) plays a crucial role in the activation and recruitment of platelets and also ensures the structural integrity of thrombi. (wikipedia.org)
  • some drugs possess receptor activity that allows them to stabilize general receptor activation, like buprenorphine in opioid dependent individuals or aripiprazole in schizophrenia, all depending on the dose and the recipient) exchanging/replacing substances or accumulating them to form a reserve (ex. (wikipedia.org)
  • Dopamine receptor activation of Ca2+/calmodulin-dependent protein kinase II can be cAMP dependent or independent. (wikipedia.org)
  • There are many additional signal cascade components that include the formation of arachidonic acid through PLA2 activity, activation of phospholipase D, Rho/Rho kinase, and ERK pathway activation initiated by agonist stimulation of the receptor. (wikipedia.org)
  • citation needed] Physiological processes mediated by the receptor include: CNS: neuronal excitation (most likely responsible for the psychedelic effects associated with 5-HT2A receptor agonists such as LSD, DMT, etc.), behavioural effects, learning, anxiety smooth muscle: contraction (in bronchi and gastrointestinal tract) vasoconstriction / vasodilation platelets: aggregation Activation of the 5-HT2A receptor with 2,5-Dimethoxy-4-iodoamphetamine (DOI) produces potent anti-inflammatory effects in several tissues including cardiovascular and gut. (wikipedia.org)
  • Activation of the 5-HT2A receptor in hypothalamus causes increases in hormonal levels of oxytocin, prolactin, ACTH, corticosterone, and renin. (wikipedia.org)
  • Role in memory and learning Activation of the 5-HT2A receptor is necessary for the effects of the "classic" psychedelics like LSD, psilocin and mescaline, which act as full or partial agonists at this receptor, and represent the three main classes of 5-HT2A agonists, the ergolines, tryptamines and phenethylamines, respectively. (wikipedia.org)
  • Stimulation of the A1 receptor has a myocardial depressant effect by decreasing the conduction of electrical impulses and suppressing pacemaker cell function, resulting in a decrease in heart rate. (wikipedia.org)
  • Upon receptor stimulation with agonist, Gαq and β-γ subunits dissociate to initiate downstream effector pathways. (wikipedia.org)
  • The GluN1/GluN2B NMDA receptor and metabotropic glutamate receptor 1 negative allosteric modulator has enhanced neuroprotection in a rat subarachnoid hemorrhage model. (amedeo.com)
  • These two receptors also have important roles in the brain, regulating the release of other neurotransmitters such as dopamine and glutamate, while the A2B and A3 receptors are located mainly peripherally and are involved in processes such as inflammation and immune responses. (wikipedia.org)
  • Heteromers consisting of adenosine A1/A2A, dopamine D2/A2A and D3/A2A, glutamate mGluR5/A2A and cannabinoid CB1/A2A have all been observed, as well as CB1/A2A/D2 heterotrimers, and the functional significance and endogenous role of these hybrid receptors is still only starting to be unravelled. (wikipedia.org)
  • Since many of these neurons express GABA, glutamate, serotonin and adenosine receptors, chemicals custom tailored to bind at these sites are most effective at altering respiratory rhythm. (wikipedia.org)
  • Especially high concentrations of this receptor on the apical dendrites of pyramidal cells in layer V of the cortex may modulate cognitive processes, working memory, and attention by enhancing glutamate release followed by a complex range of interactions with the 5-HT1A, GABAA, adenosine A1, AMPA, mGluR2/3, mGlu5, and OX2 receptors. (wikipedia.org)
  • Downregulation of post-synaptic 5-HT2A receptor is an adaptive process provoked by chronic administration of selective serotonin reuptake inhibitors (SSRIs) and classical antipsychotics. (wikipedia.org)
  • It acts as a GABAA receptor positive allosteric modulator at the barbiturate binding site of the complex and has anxiolytic effects in animals. (wikipedia.org)
  • However, in altered cardiac function, such as hypoperfusion caused by hypotension, heart attack or cardiac arrest caused by nonperfusing bradycardias, adenosine has a negative effect on physiological functioning by preventing necessary compensatory increases in heart rate and blood pressure that attempt to maintain cerebral perfusion. (wikipedia.org)
  • inverse agonist) blocking/antagonizing action (as with silent antagonists), the drug binds the receptor but does not activate it stabilizing action, the drug seems to act neither as a stimulant or as a depressant (ex. (wikipedia.org)
  • Presynaptically, it reduces synaptic vesicle release while post synaptically it has been found to stabilize the magnesium on the NMDA receptor. (wikipedia.org)