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Norketamine
Norketamine, or ''N''-desmethylketamine, is the major active metabolite of ketamine, which is formed mainly by CYP3A4. Similarly to ketamine, norketamine acts as a noncompetitive NMDA receptor antagonist (Ki = 1.7 μM and 13 μM for (''S'')-(+)-norketamine and (''R'')-(–)-norketamine, respectively), but is about 3–5 times less potent as an anesthetic in comparison. Also, similarly again to ketamine, norketamine binds to the μ- and κ-opioid receptors. Relative to ketamine, norketamine is much more potent as an antagonist of the α7-nicotinic acetylcholine receptor, and produces rapid antidepressant effects in animal models which have been reported to correlate with its activity at this receptor. However, norketamine is about 1/5 as potent as ketamine as an antidepressant in mice as per the forced swim test, and this seems also to be in accordance with its 3–5-fold reduced comparative potency ''in vivo Studies that are ''in vivo'' (Latin for "within the living"; o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ketamine
Ketamine is a dissociative anesthetic used medically for induction and maintenance of anesthesia. It is also used as a recreational drug. It is one of the safest anesthetics, as, in contrast with opiates, ether, and propofol, it suppresses neither respiration nor heart rate. Ketamine is also simple to administer and highly tolerable compared to drugs with similar effects which are flammable, irritating, or even explosive. Ketamine is a novel compound, derived from PCP, created in pursuit of a safer anesthetic with similar characteristics. Ketamine is also used for acute pain management. At anesthetic doses, ketamine induces a state of "dissociative anesthesia", a trance-like state providing pain relief, sedation, and amnesia. The distinguishing features of ketamine anesthesia are preserved breathing and airway reflexes, stimulated heart function with increased blood pressure, and moderate bronchodilation. At lower, sub-anesthetic doses, ketamine is a promising agent for pain ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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] |
Arylcyclohexylamines
Arylcyclohexylamines, also known as arylcyclohexamines or arylcyclohexanamines, are a chemical class of pharmaceutical, designer, and experimental drugs. History Phencyclidine (PCP) is believed to be the first arylcyclohexylamine with recognized anesthetic properties, but several arylcyclohexylamines were described before PCP in the scientific literature, beginning with PCA (1-phenylcyclohexan-1-amine) the synthesis of which was first published in 1907. PCE was reported in 1953 and PCMo (4-(1-phenyl-cyclohexyl)-morpholine see chart below for figure) in 1954, with PCMo described as a potent sedative. Arylcyclohexylamine anesthetics were intensively investigated at Parke-Davis, beginning with the 1956 synthesis of phencyclidine and later the related compound ketamine. The 1970s saw the debut of these compounds, especially PCP and its analogues, as illicitly used recreational drugs due to their dissociative hallucinogenic and euphoriant effects. Since that time, the class has be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
α7-nicotinic Acetylcholine 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.Pharmacology, (Rang, Dale, Ritter & Moore, , 5th ed., Churchill Livingstone 2003) p. 138. As with other nicotinic acetylcholine receptors, functional α7 receptors are pentameric .e., (α7)5 stoichiometry">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 The ileum () is the final section of the small intestine in most high ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrochloride
In chemistry, a hydrochloride is an acid salt resulting, or regarded as resulting, from the reaction of hydrochloric acid with an organic base (e.g. an amine). An alternative name is chlorhydrate, which comes from French. An archaic alternative name is muriate, derived from hydrochloric acid's ancient name: muriatic acid. Uses Converting amines into their hydrochlorides is a common way to improve their water solubility, which can be desirable for substances used in medications. The European Pharmacopoeia lists more than 200 hydrochlorides as active ingredients in medications. These hydrochlorides, compared to free bases, may more readily dissolve in the gastrointestinal tract and be absorbed into the bloodstream more quickly. Additionally, many hydrochlorides of amines have a longer shelf-life than their respective free bases. Amine hydrochlorides represent latent forms of a more reactive free base. In this regard, formation of an amine hydrochloride confers protection. This eff ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Forced Swim Test
The behavioural despair test (or Porsolt forced swimming test) is a test, centered on a rodent's response to the threat of drowning, whose result has been interpreted as measuring susceptibility to negative mood. It is commonly used to measure the effectiveness of antidepressants, although significant criticisms of its interpretation have been made. Method Animals are subjected to two trials during which they are forced to swim in an acrylic glass cylinder filled with water, and from which they cannot escape. The first trial lasts 15 minutes. Then, after 24-hours, a second trial is performed that lasts 5 minutes. The time that the test animal spends in the second trial without making any movements beyond those required to keep its head above water is measured. This immobility time is decreased by various types of antidepressants and also by electroconvulsive shock. Another common variant of this behavioural test specifically used for mice is conducted only for one trial and last ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ketones
In organic chemistry, a ketone is a functional group with the structure R–C(=O)–R', where R and R' can be a variety of carbon-containing substituents. Ketones contain a carbonyl group –C(=O)– (which contains a carbon-oxygen double bond C=O). The simplest ketone is acetone (where R and R' is methyl), with the formula . Many ketones are of great importance in biology and in industry. Examples include many sugars (ketoses), many steroids (e.g., testosterone), and the solvent acetone. Nomenclature and etymology The word ''ketone'' is derived from ''Aketon'', an old German word for ''acetone''. According to the rules of IUPAC nomenclature, ketone names are derived by changing the suffix ''-ane'' of the parent alkane to ''-anone''. Typically, the position of the carbonyl group is denoted by a number, but traditional nonsystematic names are still generally used for the most important ketones, for example acetone and benzophenone. These nonsystematic names are considered ret ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Drug Metabolites
Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, culture, and language. Humans are highly social and tend to live in complex social structures composed of many cooperating and competing groups, from families and kinship networks to political states. Social interactions between humans have established a wide variety of values, social norms, and rituals, which bolster human society. Its intelligence and its desire to understand and influence the environment and to explain and manipulate phenomena have motivated humanity's development of science, philosophy, mythology, religion, and other fields of study. Although some scientists equate the term ''humans'' with all members of the genus ''Homo'', in common usage, it generally refers to ''Homo sapiens'', the only extant member. Anatomically mode ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
General Anesthetics
General anaesthetics (or anesthetics, see spelling differences) are often defined as compounds that induce a loss of consciousness in humans or loss of righting reflex in animals. Clinical definitions are also extended to include an induced coma that causes lack of awareness to painful stimuli, sufficient to facilitate surgical applications in clinical and veterinary practice. General anaesthetics do not act as analgesics and should also not be confused with sedatives. General anaesthetics are a structurally diverse group of compounds whose mechanisms encompasses multiple biological targets involved in the control of neuronal pathways. The precise workings are the subject of some debate and ongoing research. General anesthetics elicit a state of general anesthesia. It remains somewhat controversial regarding how this state should be defined. General anesthetics, however, typically elicit several key reversible effects: immobility, analgesia, amnesia, unconsciousness, and reduced a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dissociative Drugs
Dissociatives, colloquially dissos, are a subclass of hallucinogens which distort perception of sight and sound and produce feelings of detachment – dissociation – from the environment and/or self. Although many kinds of drugs are capable of such action, dissociatives are unique in that they do so in such a way that they produce hallucinogenic effects, which may include dissociation, a general decrease in sensory experience, hallucinations, dream-like states or anesthesia. Some of these substances, which are nonselective in action and affect the dopamine and/or opioid systems, may be capable of inducing euphoria or symptoms which are more akin to the effects of certain “hard drugs” or common drugs of abuse. This is likely why dissociatives are considered to be addictive with a fair to moderate potential for abuse, unlike psychedelics. Despite some dissociatives, such as phencyclidine (PCP) possessing stimulating properties, most dissociatives seem to have a general depre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
