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Ritanserin Synthesis
Ritanserin, also known by its developmental code name R-55667, is a serotonin antagonist medication described as an anxiolytic, antidepressant, antiparkinsonian agent, and antihypertensive agent. It was chiefly investigated as a drug to treat insomnia, especially to enhance sleep quality by significantly increasing slow wave sleep by virtue of potent and concomitant 5-HT2A and 5-HT2C receptor antagonism. It was never marketed for medical use due to safety problems but is currently used in scientific research. Some of the safety liabilities that led to its discontinuation for the treatment of insomnia has led to its potential repurposing in the field of oncology. Specifically, ritanserin acts as a potent inhibitor of diacylglycerol kinase alpha (DGKα). As such, it may be used to treat certain types of glioblastoma and melanoma. It has also been used as a reference compound to identify putatively more selective and potent DGKα inhibitors to treat these forms of cancer as well ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serotonin Receptor Antagonist
A serotonin antagonist, or serotonin receptor antagonist, is a drug used to inhibit the action of serotonin and serotonergic drugs at serotonin receptor, serotonin (5-HT) receptors. Types 5-HT2A antagonists Antagonists of the 5-HT2A, 5-HT2A receptor are sometimes used as atypical antipsychotics (contrast with typical antipsychotics, which are purely dopamine antagonists). They include, but are not limited to: * Cyproheptadine blocks 5-HT2A, H1 and is a mild anticholinergic. * Methysergide is a 5-HT2A antagonist and nonselective 5-HT1, 5-HT1 receptor blocker. It causes retroperitoneal fibrosis and mediastinal fibrosis. * Quetiapine blocks 5-HT2A, 5-HT1A, 5-HT1A, dopamine receptors DRD1, D1 and DRD2, D2, histamine receptor HRH1, H1, and A1 adrenoreceptors. 5-HT2A/2C antagonists * Ketanserin Antihypertensive. Blocks 5-HT2A, 5-HT2C, 5-HT2C and Alpha 1 adrenoreceptor, Alpha 1 (A1) adrenoreceptors. * Risperidone antipsychotic * Trazodone * Nefazodone 5-HT3 antagonists Another s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Receptor Antagonist
A receptor antagonist is a type of receptor ligand or drug that blocks or dampens a biological response by binding to and blocking a receptor rather than activating it like an agonist. Antagonist drugs interfere in the natural operation of receptor proteins.Pharmacology Guide: In vitro pharmacology: concentration-response curves ." '' GlaxoWellcome.'' Retrieved on December 6, 2007. They are sometimes called blockers; examples include alpha blockers, beta b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Risperidone
Risperidone, sold under the brand name Risperdal among others, is an atypical antipsychotic used to treat schizophrenia and bipolar disorder, as well as aggressive and self-injurious behaviors associated with autism spectrum disorder. It is taken either by mouth or by injection (i.e., subcutaneous or intramuscular). The injectable versions are long-acting and last for 2–4 weeks. Common side effects include weight gain, drowsiness, fatigue, insomnia, dry mouth, constipation, elevated prolactin levels, and restlessness. Serious side effects may include the potentially permanent movement disorder tardive dyskinesia, as well as neuroleptic malignant syndrome, an increased risk of suicide, and high blood sugar levels. In older people with psychosis as a result of dementia, it may increase the risk of death. It is unknown if it is safe for use in pregnancy. Its mechanism of action is not entirely clear, but is believed to be related to its action as a dopamine and ser ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atypical Antipsychotic
The atypical antipsychotics (AAP), also known as second generation antipsychotics (SGAs) and serotonin–dopamine antagonists (SDAs), are a group of antipsychotic drugs (antipsychotic drugs in general are also known as tranquilizers and neuroleptics, although the latter is usually reserved for the '' typical antipsychotics'') largely introduced after the 1970s and used to treat psychiatric conditions. Some atypical antipsychotics have received regulatory approval (e.g. by the FDA of the US, the TGA of Australia, the MHRA of the UK) for schizophrenia, bipolar disorder, irritability in autism, and as an adjunct in major depressive disorder. Both generations of medication tend to block receptors in the brain's dopamine pathways. Atypicals are less likely than haloperidol—the most widely used typical antipsychotic—to cause extrapyramidal motor control disabilities in patients such as unsteady Parkinson's disease–type movements, body rigidity, and involuntary ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
5-HT7 Receptor
The 5-HT7 receptor is a member of the GPCR superfamily of cell surface receptors and is activated by the neurotransmitter serotonin (5-hydroxytryptamine, 5-HT). The 5-HT7 receptor is coupled to Gs (stimulates the production of the intracellular signaling molecule cAMP) and is expressed in a variety of human tissues, particularly in the brain, the gastrointestinal tract, and in various blood vessels. This receptor has been a drug development target for the treatment of several clinical disorders. The 5-HT7 receptor is encoded by the ''HTR7'' gene, which in humans is transcribed into 3 different splice variants. Function When the 5-HT7 receptor is activated by serotonin, it sets off a cascade of events starting with release of the stimulatory G protein Gs from the GPCR complex. Gs in turn activates adenylate cyclase which increases intracellular levels of the second messenger cAMP. The 5-HT7 receptor plays a role in smooth muscle relaxation within the vasculature ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
5-HT6 Receptor
The 5HT6 receptor is a subtype of 5HT receptor that binds the endogenous neurotransmitter serotonin (5-hydroxytryptamine, 5HT). It is a G protein-coupled receptor (GPCR) that is coupled to Gs and mediates excitatory neurotransmission. ''HTR6'' denotes the human gene encoding for the receptor. Distribution The 5HT6 receptor is expressed almost exclusively in the brain. It is distributed in various areas including, but not limited to, the olfactory tubercle, cerebral cortex ( frontal and entorhinal regions), nucleus accumbens, striatum, caudate nucleus, hippocampus, and the molecular layer of the cerebellum. Based on its abundance in extrapyramidal, limbic, and cortical regions it can be suggested that the 5HT6 receptor plays a role in functions like motor control, emotionality, cognition, and memory. Function Blockade of central 5HT6 receptors has been shown to increase glutamatergic and cholinergic neurotransmission in various brain areas, whereas activation enh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
5-HT5A Receptor
5-Hydroxytryptamine (serotonin) receptor 5A, also known as HTR5A, is a protein that in humans is encoded by the ''HTR5A'' gene. Agonists and Receptor antagonist, antagonists for 5-HT receptors, as well as serotonin uptake inhibitors, present promnesic (memory-promoting) and/or anti-amnesic effects under different conditions, and 5-HT receptors are also associated with neural changes. Function The gene described in this record is a member of 5-HT receptor, 5-hydroxytryptamine receptor family and encodes a multi-pass membrane protein that functions as a receptor for 5-hydroxytryptamine and couples to G proteins, negatively influencing cAMP levels via Gi and Go. This protein has been shown to function in part through the regulation of intracellular Ca2+ mobilization. The 5-HT5A receptor has been shown to be functional in a native expression system. Rodents have been shown to possess two functional 5-HT5 receptor subtypes, 5-HT5A and 5-HT5B, however while humans possess a gene cod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
5-HT2B Receptor
5-Hydroxytryptamine receptor 2B (5-HT2B) also known as serotonin receptor 2B is a protein that in humans is encoded by the ''HTR2B'' gene. 5-HT2B is a member of the 5-HT2 receptor, 5-HT2 receptor family that binds the neurotransmitter serotonin (5-hydroxytryptamine, 5-HT). Like all 5-HT2 receptors, the 5-HT2B receptor is Gq protein, Gq/G11-protein coupled, leading to downstream activation of phospholipase C. Tissue distribution and function First discovered in the stomach of rats, 5-HT2B was challenging to characterize initially because of its structural similarity to the other 5-HT2 receptors, particularly 5-HT2C. The 5-HT2 receptors (of which the 5-HT2B receptor is a subtype) mediate many of the central and peripheral physiologic functions of serotonin. Cardiovascular effects include contraction of blood vessels and shape changes in platelets; central nervous system (CNS) effects include neuronal sensitization to tactile stimuli and mediation of some of the effects of halluci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
5-HT1D Receptor
5-hydroxytryptamine (serotonin) receptor 1D, also known as HTR1D, is a 5-HT receptor, but also denotes the human gene encoding it. 5-HT1D acts on the central nervous system, and affects locomotion and anxiety. It also induces vasoconstriction in the brain. Tissue distribution 5HT1D receptors are found at low levels in the basal ganglia (globus pallidus, substantia nigra, caudate putamen), the hippocampus, and in the cortex. Structure 5HT1D receptor is a G protein linked receptor that activates an intracellular messenger cascade to produce an inhibitory response by decreasing cellular levels of cAMP. The 5HT1D is a 7-TM receptor. A large intercellular loop between TM-5 and TM-6 is believed to be associated with coupling to a second messenger. Agonists might bind in a manner that utilizes an aspartate residue in TM-3 and residues in the TM-4, TM-5 and TM-6. A human clone containing an intronless open reading frame was found to encode 377 amino acids of the 5HT1D receptor. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
5-HT1A Receptor
The serotonin 1A receptor (or 5-HT1A receptor) is a subtype of serotonin receptors, or 5-HT receptors, that binds serotonin, also known as 5-HT, a neurotransmitter. 5-HT1A is expressed in the brain, spleen, and neonatal kidney. It is a G protein-coupled receptor (GPCR), coupled to the Gi protein, and its activation in the brain mediates hyperpolarization and reduction of firing rate of the postsynaptic neuron. In humans, the serotonin 1A receptor is encoded by the HTR1A gene. Distribution The 5-HT1A receptor is the most widespread of all the 5-HT receptors. In the central nervous system, 5-HT1A receptors exist in the cerebral cortex, hippocampus, Septum pellucidum, septum, amygdala, and Raphe nuclei, raphe nucleus in high densities, while low amounts also exist in the basal ganglia and thalamus. The 5-HT1A receptors in the raphe nucleus are largely somatodendritic autoreceptors, whereas those in other areas such as the hippocampus are postsynaptic receptors. Function Neur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpha-2 Adrenergic Receptor
The alpha-2 (α2) adrenergic receptor (or adrenoceptor) is a G protein-coupled receptor (GPCR) associated with the Gi alpha subunit, Gi heterotrimeric G-protein. It consists of three highly homologous subtypes, including α2A-adrenergic, α2A-, α2B-adrenergic, α2B-, and α2C-adrenergic, α2C-adrenergic. Some species other than humans express a fourth α2D-adrenergic receptor as well. Catecholamines like norepinephrine (noradrenaline) and epinephrine (adrenaline) signal through the α2-adrenergic receptor in the central nervous system, central and peripheral nervous systems. Cellular localization The Alpha-2A adrenergic receptor, α2A adrenergic receptor is localised in the following central nervous system (CNS) structures: * Brainstem (especially the locus coeruleus as presynaptic & somatodendritic autoreceptor ) * Midbrain * Hypothalamus * Olfactory system * Hippocampus * Spinal cord * Cerebral cortex * Cerebellum * Septum Whereas the Alpha-2B adrenergic receptor, α2B adren ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpha-1 Adrenergic Receptor
alpha-1 (α1) adrenergic are G protein-coupled receptors (GPCRs) associated with the Gq alpha subunit, Gq heterotrimeric G protein. α1-adrenergic receptors are subdivided into three highly homologous subtypes, i.e., α1A-adrenergic, α1A-, α1B-adrenergic, α1B-, and α1D-adrenergic, α1D-adrenergic receptor subtypes. There is no α1C receptor. At one time, there was a subtype known as α1C, but it was found to be identical to the previously discovered α1A receptor subtype. To avoid confusion, naming was continued with the letter D. Catecholamines like norepinephrine (noradrenaline) and epinephrine (adrenaline) signal through the α1-adrenergic receptors in the central nervous system, central and peripheral nervous systems. The crystal structure of the α1B-adrenergic receptor subtype has been determined in complex with the inverse agonist (+)-cyclazosin. Effects The α1-adrenergic receptor has several general functions in common with the Alpha-2 adrenergic receptor, α2-adrene ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
