|
Adenosine A1 Receptor
The adenosine A1 receptor (A1AR) is one member of the adenosine receptor group of G protein-coupled receptors with adenosine as endogenous ligand. Biochemistry A1 receptors are implicated in sleep promotion by inhibiting wake-promoting cholinergic neurons in the basal forebrain. A1 receptors are also present in smooth muscle throughout the vascular system. The adenosine A1 receptor has been found to be ubiquitous throughout the entire body. Signaling Activation of the adenosine A1 receptor by an agonist causes binding of Gi1/2/3 or Go protein. Binding of Gi1/2/3 causes an inhibition of adenylate cyclase and, therefore, a decrease in the cAMP concentration. An increase of the inositol triphosphate/ diacylglycerol concentration is caused by an activation of phospholipase C, whereas the elevated levels of arachidonic acid are mediated by DAG lipase, which cleaves DAG to form arachidonic acid. Several types of potassium channels are activated but N-, P-, and Q-type calc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adenosine Receptor
The adenosine receptors (or P1 receptors) are a class of Purinergic receptor, purinergic G protein-coupled receptors with adenosine as the endogenous ligand (biochemistry), ligand. There are four known types of adenosine receptors in humans: Adenosine A1 receptor, A1, Adenosine A2A receptor, A2A, Adenosine A2B receptor, A2B and Adenosine A3 receptor, A3; each is encoded by a different gene. The adenosine receptors are commonly known for their antagonists caffeine, theophylline, and theobromine, whose action on the receptors produces the stimulating effects of coffee, tea and chocolate. Pharmacology Each type of adenosine receptor has different functions, although with some overlap. For instance, both A1 receptors and A2A play roles in the heart, regulating myocardial oxygen consumption and Coronary circulation, coronary blood flow, while the A2A receptor also has broader anti-inflammatory effects throughout the body. These two receptors also have important roles in the brain, r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Synapse
Chemical synapses are biological junctions through which neurons' signals can be sent to each other and to non-neuronal cells such as those in muscles or glands. Chemical synapses allow neurons to form circuits within the central nervous system. They are crucial to the biological computations that underlie perception and thought. They allow the nervous system to connect to and control other systems of the body. At a chemical synapse, one neuron releases neurotransmitter molecules into a small space (the synaptic cleft) that is adjacent to another neuron. The neurotransmitters are contained within small sacs called synaptic vesicles, and are released into the synaptic cleft by exocytosis. These molecules then bind to neurotransmitter receptors on the postsynaptic cell. Finally, the neurotransmitters are cleared from the synapse through one of several potential mechanisms including enzymatic degradation or re-uptake by specific transporters either on the presynaptic cell or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rolofylline
Rolofylline (KW-3902) is an experimental diuretic which acts as a selective adenosine A1 receptor antagonist. It was discovered at NovaCardia, Inc. which was purchased by Merck & Co., Inc. in 2007. Development of rolofylline was terminated on September 1, 2009, after the results of a large clinical trial (PROTECT) showed the drug to be no better than placebo for patients with acute heart failure. Participants given rolofylline did show some improvement in shortness of breath, but the drug did not prevent kidney damage or have any significant effect on overall treatment success. Rolofylline was also associated with a higher incidence of seizures and stroke Stroke is a medical condition in which poor cerebral circulation, blood flow to a part of the brain causes cell death. There are two main types of stroke: brain ischemia, ischemic, due to lack of blood flow, and intracranial hemorrhage, hemor .... References Adenosine receptor antagonists Diuretics Xanthines [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tonapofylline
Tonapofylline (BG-9928) is a drug which acts as a potent and selective antagonist for the adenosine A1 receptor. It was developed as a potential agent for the treatment of heart failure by increasing sodium excretion by the kidneys, and reached Phase III human clinical trials, showing reasonable efficacy with a good safety profile. However, it was ultimately not adopted for medical use, though it continues to be used in research. Its activity as a phosphodiesterase inhibitor does not appear to have been tested, though most related xanthine Xanthine ( or , from Ancient Greek for its yellowish-white appearance; archaically xanthic acid; systematic name 3,7-dihydropurine-2,6-dione) is a purine base found in most human body tissues and fluids, as well as in other organisms. Several ... derivatives are phosphodiesterase inhibitors as well as adenosine receptor antagonists. See also * DPCPX References Adenosine receptor antagonists Xanthines Propyl compounds Car ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bamifylline
Bamifylline is a drug of the xanthine chemical class which acts as a selective adenosine A1 receptor antagonist. See also * Theophylline * Caffeine Caffeine is a central nervous system (CNS) stimulant of the methylxanthine chemical classification, class and is the most commonly consumed Psychoactive drug, psychoactive substance globally. It is mainly used for its eugeroic (wakefulness pr ... References Adenosine receptor antagonists Enones Hydroxyethyl compounds Xanthines {{cardiovascular-drug-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
8-Cyclopentyl-1,3-dipropylxanthine
8-Cyclopentyl-1,3-dipropylxanthine (DPCPX, PD-116,948) is a drug which acts as a potent and selective antagonist for the adenosine A1 receptor. It has high selectivity for A1 over other adenosine receptor subtypes, but as with other xanthine derivatives DPCPX also acts as a phosphodiesterase inhibitor, and is almost as potent as rolipram at inhibiting PDE4. It has been used to study the function of the adenosine A1 receptor in animals, which has been found to be involved in several important functions such as regulation of breathing and activity in various regions of the brain, and DPCPX has also been shown to produce behavioural effects such as increasing the hallucinogen-appropriate responding produced by the 5-HT2A agonist DOI, and the dopamine release induced by MDMA, as well as having interactions with a range of anticonvulsant drugs. See also * DMPX * CPX * Xanthine Xanthine ( or , from Ancient Greek for its yellowish-white appearance; archaically xanthic aci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
8-Cyclopentyl-1,3-dimethylxanthine
8-Cyclopentyl-1,3-dimethylxanthine (8-Cyclopentyltheophylline, 8-CPT, CPX) is a drug which acts as a potent and selective antagonist for the adenosine receptors, with some selectivity for the A1 receptor subtype, as well as a non-selective phosphodiesterase inhibitor. It has stimulant effects in animals with slightly higher potency than caffeine. See also * 8-Chlorotheophylline * 8-Phenyltheophylline * DMPX * DPCPX * Xanthine Xanthine ( or , from Ancient Greek for its yellowish-white appearance; archaically xanthic acid; systematic name 3,7-dihydropurine-2,6-dione) is a purine base found in most human body tissues and fluids, as well as in other organisms. Several ... References Adenosine receptor antagonists Phosphodiesterase inhibitors Xanthines Cyclopentyl compounds {{nervous-system-drug-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CGS-15943
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 derivative, instead being a triazoloquinazoline. Consequently, CGS-15943 has the advantage over most xanthine derivatives that it is not a phosphodiesterase inhibitor, and so has more a specific pharmacological effects profile. It produces similar effects to caffeine Caffeine is a central nervous system (CNS) stimulant of the methylxanthine chemical classification, class and is the most commonly consumed Psychoactive drug, psychoactive substance globally. It is mainly used for its eugeroic (wakefulness pr ... in animal studies, though with higher potency. See also * ATL-444 * SCH-58261 References Adenosine receptor antagonists Experimental drugs 2-Furyl compounds {{nervous-system-drug-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theophylline
Theophylline, also known as 1,3-dimethylxanthine, is a drug that inhibits phosphodiesterase and blocks adenosine receptors. It is used to treat chronic obstructive pulmonary disease (COPD) and asthma. Its pharmacology is similar to other methylxanthine drugs (e.g., theobromine and caffeine). Trace amounts of theophylline are naturally present in tea, coffee, chocolate, yerba maté, guarana, and kola nut. The name 'theophylline' derives from "Thea"—the former genus name for tea + Legacy Greek φύλλον (phúllon, "leaf") + -ine. Medical uses The main actions of theophylline involve: * relaxing bronchial smooth muscle * increasing heart muscle contractility and efficiency (positive inotrope) * increasing heart rate (positive chronotropic) * increasing blood pressure * increasing renal blood flow * anti-inflammatory effects * central nervous system stimulatory effect, mainly on the medullary respiratory center The main therapeutic uses of theophylline are for treat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
N6-Cyclopentyladenosine
''N''6-Cyclopentyladenosine (CPA) is a drug which acts as a selective adenosine A1 receptor agonist. It has mainly cardiovascular effects with only subtle alterations of behavior. CPA is widely used in scientific research into the adenosine receptor The adenosine receptors (or P1 receptors) are a class of Purinergic receptor, purinergic G protein-coupled receptors with adenosine as the endogenous ligand (biochemistry), ligand. There are four known types of adenosine receptors in humans: Aden ...s and has been used to derive a large family of derivatives. See also * ''N''6-Methyladenosine References Nucleosides Purines Adenosine receptor agonists Hydroxymethyl compounds {{cardiovascular-drug-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CCPA (biochemistry)
2-Chloro-''N''6-cyclopentyladenosine (CCPA) is a specific receptor agonist for the Adenosine A1 receptor. It is similar to ''N''6-cyclopentyladenosine. Initially developed to probe the physiological and pharmacological roles of adenosine receptors, CCPA has become a pivotal tool in cardiovascular and neurological research. Due to CCPA's high affinity for Adenosine A1 receptors, its tritiated derivative 3H">sup>3HCPA can be used as a diagnostic tool for detecting the receptors in tissue with low receptor density. Chemical Structure and Properties CCPA is chemically characterized by the addition of a chlorine atom at the 2-position and a cyclopentyl group at the N6 position of the adenosine molecule. These modifications enhance its receptor selectivity and binding affinity. The molecular formula of CCPA is C15H19ClN5O4, with a molecular weight of approximately 367.80 g/mol. Pharmacological Profile Affinity and Selectivity for Adenosine Receptors CCPA exhibits a high ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adenosine A2A Receptor
The adenosine A2A receptor, also known as ADORA2A, is an adenosine receptor, and also denotes the human gene encoding it. Structure This protein is a member of the G protein-coupled receptor (GPCR) family which possess seven transmembrane alpha helices, as well as an extracellular N-terminus and an intracellular C-terminus. Furthermore, located in the intracellular side close to the membrane is a small alpha helix, often referred to as helix 8 (H8). The crystallographic structure of the adenosine A2A receptor reveals a ligand binding pocket distinct from that of other structurally determined GPCRs (i.e., the beta-2 adrenergic receptor and rhodopsin).; Below this primary ( orthosteric) binding pocket lies a secondary ( allosteric) binding pocket. The crystal-structure of A2A bound to the antagonist ZM241385 (PDB code: 4EIY) showed that a sodium-ion can be found in this location of the protein, thus giving it the name 'sodium-ion binding pocket'. Heteromers The actions of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
