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(2R,6R)-Hydroxynorketamine
Hydroxynorketamine (HNK), or 6-hydroxynorketamine, is a minor metabolite of the anesthetic, dissociative, and antidepressant drug ketamine. It is formed by hydroxylation of the intermediate norketamine, another metabolite of ketamine. As of late 2019, (2''R'',6''R'')-HNK is in clinical trials for the treatment of depression. The major metabolite of ketamine is norketamine (80%). Norketamine is secondarily converted into 4-, 5-, and 6-hydroxynorketamines (15%), mainly HNK (6-hydroxynorketamine). Ketamine is also transformed into hydroxyketamine (5%). As such, bioactivated HNK comprises less than 15% of a dose of ketamine. Pharmacology In contrast to ketamine and norketamine, HNK is inactive as an anesthetic and psychostimulant. In accordance, it has only very weak affinity for the NMDA receptor (Ki = 21.19 μM and > 100 μM for (2''S'',6''S'')-HNK and (2''R'',6''R'')-HNK, respectively). However, HNK does still show biological activity, having been found to act as a potent and se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Stereoisomer
In stereochemistry, stereoisomerism, or spatial isomerism, is a form of isomerism in which molecules have the same molecular formula and sequence of bonded atoms (constitution), but differ in the three-dimensional orientations of their atoms in space. This contrasts with structural isomers, which share the same molecular formula, but the bond connections or their order differs. By definition, molecules that are stereoisomers of each other represent the same structural isomer. Enantiomers Enantiomers, also known as optical isomers, are two stereoisomers that are related to each other by a reflection: they are mirror images of each other that are non-superposable. Human hands are a macroscopic analog of this. Every stereogenic center in one has the opposite configuration in the other. Two compounds that are enantiomers of each other have the same physical properties, except for the direction in which they rotate polarized light and how they interact with different enantiomers of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Alpha-7 Nicotinic Receptor
The alpha-7 nicotinic receptor, also known as the α7 receptor, is a type of nicotinic acetylcholine receptor implicated in long-term memory, consisting entirely of α7 subunits. As with other nicotinic acetylcholine receptors, functional α7 receptors are pentameric stoichiometry.html" ;"title=".e., (α7)5 stoichiometry">.e., (α7)5 stoichiometry It is located in the brain, spleen, and lymphocytes of lymph nodes where activation yields Excitatory postsynaptic potential, post- and excitatory presynaptic potential, presynaptic excitation, mainly by increased Ca2+ permeability. Further, recent work has implicated this receptor as being important for generation of adult mammal neurons in the retina. Functional α7 receptors are present in the submucous plexus neurons of the guinea-pig ileum. Medical relevance The Recent work has demonstrated a potential role in reducing inflammatory neurotoxicity in stroke, myocardial infarction, sepsis, and Alzheimer's disease. The α7 re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Dizocilpine
Dizocilpine ( INN), also known as MK-801, is a pore blocker of the NMDA receptor, a glutamate receptor, discovered by a team at Merck in 1982. Glutamate is the brain's primary excitatory neurotransmitter. The channel is normally blocked with a magnesium ion and requires depolarization of the neuron to remove the magnesium and allow the glutamate to open the channel, causing an influx of calcium, which then leads to subsequent depolarization. Dizocilpine binds inside the ion channel of the receptor at several of PCP's binding sites thus preventing the flow of ions, including calcium (Ca2+), through the channel. Dizocilpine blocks NMDA receptors in a use- and voltage-dependent manner, since the channel must open for the drug to bind inside it. The drug acts as a potent anti-convulsant and probably has dissociative anesthetic properties, but it is not used clinically for this purpose because of the discovery of brain lesions, called Olney's lesions (see below), in laboratory rats. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
AMPA Receptor
The α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPA receptor, AMPAR, or quisqualate receptor) is an ionotropic receptor, ionotropic glutamate receptor (iGluR) and predominantly sodium ion channel that mediates fast excitatory neurotransmission in the Central nervous system, central nervous system (CNS). Its activation by the neurotransmitter Glutamate (neurotransmitter), glutamate facilitates rapid neuronal communication, essential for various brain functions, including learning and memory. Its name is derived from the ability to be activated by the artificial glutamate analog AMPA. The receptor was initially named the "Quisqualic acid, quisqualate receptor" by Watkins and colleagues after the naturally occurring agonist quisqualic acid, quisqualate. Later, the receptor was designated as the "AMPA receptor" following the development of the selective agonist AMPA by Tage Honore and colleagues at the Royal Danish School of Pharmacy in Copenhagen. The ''GRIA2''- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Traxoprodil
Traxoprodil (developmental code name CP-101606) is a drug developed by Pfizer which acts as an NMDA antagonist, selective for the NR2B subunit. It has neuroprotective, analgesic, and anti-Parkinsonian effects in animal studies. Traxoprodil has been researched in humans as a potential treatment to lessen the damage to the brain after stroke, but results from clinical trials showed only modest benefit. The drug was found to cause EKG abnormalities (QT prolongation) and its clinical development was stopped. More recent animal studies have suggested traxoprodil may exhibit rapid-acting antidepressant effects similar to those of ketamine, although there is some evidence for similar psychoactive side effects and abuse potential at higher doses, which might limit clinical acceptance of traxoprodil for this application. Traxoprodil showed ketamine-like rapidly-acting antidepressant effects in a small clinical trial of 30 patients with depression who were non-responders to 6 w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Lanicemine
Lanicemine (AZD6765) is a low-trapping NMDA receptor antagonist that was under drug development, development by AstraZeneca for the management of severe and treatment-resistant depression. Lanicemine differs from ketamine in that it is a ''low-trapping'' NMDA receptor antagonist, showing similar rapid-acting antidepressant effects to ketamine in clinical trials but with little or no psychotomimetic side effects. However, lanicemine did not meet study endpoints, and its development was terminated by AstraZeneca in 2013. See also * 4-Chlorokynurenine * AD-1211 * Apimostinel * CERC-301 * Diphenidine * Ephenidine * Esketamine * Lefetamine * Memantine * Methoxphenidine * MT-45 * Rapastinel References {{Ionotropic glutamate receptor modulators Abandoned drugs Phenyl compounds NMDA receptor antagonists 1,2-Diarylethylamines 2-Pyridyl compounds ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Memantine
Memantine, sold under the brand name Namenda among others, is a medication used to slow the progression of moderate-to-severe Alzheimer's disease. It is taken by mouth. Common side effects include headache, constipation, sleepiness, and dizziness. Severe side effects may include blood clots, psychosis, and heart failure. It is believed to work by acting on NMDA receptors, working as a pore blocker of these ion channels. Memantine was first discovered in 1963. It was approved for medical use in Germany in 1989, in the European Union in 2002, and in the United States in 2003. It is available as a generic medication. In 2022, it was the 150th most commonly prescribed medication in the United States, with more than 3million prescriptions. Medical uses Alzheimer's disease and dementia Memantine is used to treat moderate-to-severe Alzheimer's disease, especially for people who are intolerant of or have a contraindication to AChE (acetylcholinesterase) inhibitors.NICE review ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Dizocilpine
Dizocilpine ( INN), also known as MK-801, is a pore blocker of the NMDA receptor, a glutamate receptor, discovered by a team at Merck in 1982. Glutamate is the brain's primary excitatory neurotransmitter. The channel is normally blocked with a magnesium ion and requires depolarization of the neuron to remove the magnesium and allow the glutamate to open the channel, causing an influx of calcium, which then leads to subsequent depolarization. Dizocilpine binds inside the ion channel of the receptor at several of PCP's binding sites thus preventing the flow of ions, including calcium (Ca2+), through the channel. Dizocilpine blocks NMDA receptors in a use- and voltage-dependent manner, since the channel must open for the drug to bind inside it. The drug acts as a potent anti-convulsant and probably has dissociative anesthetic properties, but it is not used clinically for this purpose because of the discovery of brain lesions, called Olney's lesions (see below), in laboratory rats. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Nature (journal)
''Nature'' is a British weekly scientific journal founded and based in London, England. As a multidisciplinary publication, ''Nature'' features Peer review, peer-reviewed research from a variety of academic disciplines, mainly in science and technology. It has core editorial offices across the United States, continental Europe, and Asia under the international scientific publishing company Springer Nature. ''Nature'' was one of the world's most cited scientific journals by the Science Edition of the 2022 ''Journal Citation Reports'' (with an ascribed impact factor of 50.5), making it one of the world's most-read and most prestigious academic journals. , it claimed an online readership of about three million unique readers per month. Founded in the autumn of 1869, ''Nature'' was first circulated by Norman Lockyer and Alexander MacMillan (publisher), Alexander MacMillan as a public forum for scientific innovations. The mid-20th century facilitated an editorial expansion for the j ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Forced Swim Test
''Forced'' is a single-player and co-op action role-playing game developed by BetaDwarf, released in October 2013 for Windows, OS X and Linux through the Steam platform as well as Wii U. It is about gladiators fighting for their freedom in a fantasy arena where they are assisted by a spirit-like character called Balfus. Gameplay consists of selecting a weapon class and abilities to combat the various enemies of each arena, while solving puzzles using the help of Balfus. BetaDwarf was formed by a small group of students in 2011, who began developing the game in an unused classroom in Aalborg University – Copenhagen, Denmark. They were removed months later and launched a successful Kickstarter campaign involving an Imgur picture which documented their progress. ''Forced'' received moderate to favorable reviews with most critics praising its competitive gameplay and puzzle-system. The game's weak plot, technical glitches and excess difficulty were the negative highlights. It won th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
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] [Amazon] |
Dehydronorketamine
Dehydronorketamine (DHNK), or 5,6-dehydronorketamine, is a minor metabolite of ketamine which is formed by dehydrogenation of its metabolite norketamine. Though originally considered to be inactive, DHNK has been found to act as a potent and selective negative allosteric modulator of the α7-nicotinic acetylcholine receptor ( IC50 = 55 nM). For this reason, similarly to hydroxynorketamine (HNK), it has been hypothesized that DHNK may have the capacity to produce rapid antidepressant effects. However, unlike ketamine, norketamine, and HNK, DHNK has been found to be inactive in the forced swim test (FST) in mice at doses up to 50 mg/kg. DHNK is inactive at the α3β4-nicotinic acetylcholine receptor (IC50 > 100 μM) and is only very weakly active at the NMDA receptor (Ki = 38.95 μM for (''S'')-(+)-DHNK). It can be detected 7–10 days after a modest dose of ketamine, and because of this, is useful in drug detection assays. See also * Arketamine * Esketamine Esketam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
