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Catechol-O-methyltransferase
Catechol-''O''-methyltransferase (COMT; ) is one of several enzymes that degrade catecholamines (neurotransmitters such as dopamine, epinephrine, and norepinephrine), catecholestrogens, and various drugs and substances having a catechol structure. In humans, catechol-''O''-methyltransferase protein is encoded by the COMT gene. Two isoforms of COMT are produced: the soluble short form (S-COMT) and the membrane bound long form (MB-COMT). As the regulation of catecholamines is impaired in a number of medical conditions, several pharmaceutical drugs target COMT to alter its activity and therefore the availability of catecholamines. COMT was first discovered by the biochemist Julius Axelrod in 1957. Function Catechol-''O''-methyltransferase is involved in the inactivation of the catecholamine neurotransmitters (dopamine, epinephrine, and norepinephrine). The enzyme introduces a methyl group to the catecholamine, which is donated by S-adenosyl methionine (SAM). Any compound having a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parkinson's Disease
Parkinson's disease (PD), or simply Parkinson's, is a long-term degenerative disorder of the central nervous system that mainly affects the motor system. The symptoms usually emerge slowly, and as the disease worsens, non-motor symptoms become more common. The most obvious early symptoms are tremor, rigidity, slowness of movement, and difficulty with walking. Cognitive and behavioral problems may also occur with depression, anxiety, and apathy occurring in many people with PD. Parkinson's disease dementia becomes common in the advanced stages of the disease. Those with Parkinson's can also have problems with their sleep and sensory systems. The motor symptoms of the disease result from the death of cells in the substantia nigra, a region of the midbrain, leading to a dopamine deficit. The cause of this cell death is poorly understood, but involves the build-up of misfolded proteins into Lewy bodies in the neurons. Collectively, the main motor symptoms are also known as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Catecholestrogen
A catechol estrogen is a steroidal estrogen that contains catechol (1,2-dihydroxybenzene) within its structure. The catechol estrogens are endogenous metabolites of estradiol and estrone and include the following compounds: * 2-Hydroxylated: ** 2-Hydroxyestradiol ** 2-Hydroxyestrone ** 2-Hydroxyestriol * 4-Hydroxylated: ** 4-Hydroxyestradiol ** 4-Hydroxyestrone ** 4-Hydroxyestriol The most abundant catechol estrogen in serum and urine is 2-hydroxyestrone, with 2-hydroxyestradiol and 2-hydroxyestriol also being formed, while the principal 4-hydroxy catechol estrogen, 4-hydroxyestrone, is present in only small amounts in urine. 4-Hydroxyestriol has been detected in the urine of pregnant women. The catechol estrogens are formed from estradiol and estrone by cytochrome P450 enzymes predominantly in the liver but also in extrahepatic tissues, and are metabolized by catechol O-methyltransferase (COMT) into methoxylated estrogens such as 2-methoxyestradiol and 4-methoxyestro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Entacapone
Entacapone, sold under the brand name Comtan among others, is a medication commonly used in combination with other medications for the treatment of Parkinson's disease. Entacapone together with levodopa and carbidopa allows levodopa to have a longer effect in the brain and reduces Parkinson's disease signs and symptoms for a greater length of time than levodopa and carbidopa therapy alone. Entacapone is a selective and reversible inhibitor of the enzyme catechol-''O''-methyltransferase (COMT). When taken together with levodopa (L-DOPA) and carbidopa, entacapone stops catechol-''O''-methyltransferase from breaking down and metabolizing levodopa, resulting in an overall increase of levodopa remaining in the brain and body. Carbidopa/levodopa/entacapone (Stalevo), a medication developed by Orion Pharma and marketed by Novartis, is a single tablet formulation that contains levodopa, carbidopa, and entacapone. Medical uses Entacapone is used in addition to levodopa and carb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
3-methoxytyramine
3-Methoxytyramine (3-MT), also known as 3-methoxy-4-hydroxyphenethylamine, is a human trace amine that occurs as a metabolite of the neurotransmitter dopamine. It is formed by the introduction of a methyl group to dopamine by the enzyme catechol-O-methyl transferase (COMT). 3-MT can be further metabolized by the enzyme monoamine oxidase (MAO) to form homovanillic acid (HVA), which is then typically excreted in the urine. Originally thought to be physiologically inactive, 3-MT has recently been shown to act as an agonist of human TAAR1. Occurrence 3-Methoxytyramine occurs naturally in the prickly pear cactus (genus ''Opuntia''), and is in general widespread throughout the Cactaceae. It has also been found in crown gall tumors on ''Nicotiana'' sp. In humans, 3-methoxytyramine is a trace amine that occurs as a metabolite of dopamine. See also * Tyramine Tyramine ( ) (also spelled tyramin), also known under several other names, is a naturally occurring trace amine d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prefrontal Cortex
In mammalian brain anatomy, the prefrontal cortex (PFC) covers the front part of the frontal lobe of the cerebral cortex. The PFC contains the Brodmann areas BA8, BA9, BA10, BA11, BA12, BA13, BA14, BA24, BA25, BA32, BA44, BA45, BA46, and BA47. The basic activity of this brain region is considered to be orchestration of thoughts and actions in accordance with internal goals. Many authors have indicated an integral link between a person's will to live, personality, and the functions of the prefrontal cortex. This brain region has been implicated in executive functions, such as planning, decision making, short-term memory, personality expression, moderating social behavior and controlling certain aspects of speech and language. Executive function relates to abilities to differentiate among conflicting thoughts, determine good and bad, better and best, same and different, future consequences of current activities, working toward a defined goal, prediction of outcomes, e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dopamine Transporter
The dopamine transporter (also dopamine active transporter, DAT, SLC6A3) is a membrane-spanning protein that pumps the neurotransmitter dopamine out of the synaptic cleft back into cytosol. In the cytosol, other transporters sequester the dopamine into vesicles for storage and later release. Dopamine reuptake via DAT provides the primary mechanism through which dopamine is cleared from synapses, although there may be an exception in the prefrontal cortex, where evidence points to a possibly larger role of the norepinephrine transporter. DAT is implicated in a number of dopamine-related disorders, including attention deficit hyperactivity disorder, bipolar disorder, clinical depression, alcoholism, eating disorders, and substance use disorder. The gene that encodes the DAT protein is located on human chromosome 5, consists of 15 coding exons, and is roughly 64 kbp long. Evidence for the associations between DAT and dopamine related disorders has come from a type of genetic p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vanillylmandelic Acid
Vanillylmandelic acid (VMA) is a chemical intermediate in the synthesis of artificial vanilla flavorings and is an end-stage metabolite of the catecholamines ( dopamine, epinephrine, and norepinephrine). It is produced via intermediary metabolites. Chemical synthesis VMA synthesis is the first step of a two-step process practiced by Rhodia since the 1970s to synthesize artificial vanilla. Specifically the reaction entails the condensation of guaiacol and glyoxylic acid in an ice cold, aqueous solution with sodium hydroxide. Biological elimination VMA is found in the urine, along with other catecholamine metabolites, including homovanillic acid (HVA), metanephrine, and normetanephrine. In timed urine tests the quantity excreted (usually per 24 hours) is assessed along with creatinine clearance, and the quantity of cortisols, catecholamines, and metanephrines excreted is also measured. Clinical significance Urinary VMA is elevated in patients with tumors that secrete ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
3,4-Dihydroxymandelic Acid
3,4-Dihydroxymandelic acid (DHMA, DOMA) is a metabolite of norepinephrine Norepinephrine (NE), also called noradrenaline (NA) or noradrenalin, is an organic chemical in the catecholamine family that functions in the brain and body as both a hormone and neurotransmitter. The name "noradrenaline" (from Latin '' ad'', .... References Phenolic human metabolites Alpha hydroxy acids Catechols Acetic acids Triols {{Aromatic-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methoxyhydroxyphenylglycol
3-Methoxy-4-hydroxyphenylglycol (MHPG, MOPEG) is a metabolite of norepinephrine degradation. In the brain, it is the principal norepinephrine metabolite. It is released into the blood and cerebrospinal fluid, and a blood sample of it may therefore be an indication of recent sympathetic nervous system activity. Low levels of MHPG in the blood and cerebrospinal fluid are associated with anorexia nervosa and pathological gambling Problem gambling or ludomania is repetitive gambling behavior despite harm and negative consequences. Problem gambling may be diagnosed as a mental disorder according to ''DSM-5'' if certain diagnostic criteria are met. Pathological gambling is ..., indicating that norepinephrine may play a role in these behaviors. References {{DEFAULTSORT:Methoxy-4-hydroxyphenylglycol, 3- O-methylated natural phenols Phenolic human metabolites Polyols ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dihydroxyphenylethylene Glycol
Dihydroxyphenylethylene glycol (DOPEG) is a metabolite of norepinephrine through monoamine oxidase Monoamine oxidases (MAO) () are a family of enzymes that catalyze the oxidation of monoamines, employing oxygen to clip off their amine group. They are found bound to the outer membrane of mitochondria in most cell types of the body. The first .... References Catechols Phenolic human metabolites {{aromatic-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metanephrine
Metanephrine (metadrenaline) is a metabolite of epinephrine (adrenaline) created by action of catechol-O-methyl transferase on epinephrine. An article in the ''Journal of the American Medical Association'', 2002, indicated that the measurement of plasma free levels of the metanephrines group of molecules (including metanephrine and normetanephrine) is the best tool in the diagnosis of pheochromocytoma, an adrenal medullary neoplasm. Image:Adrenalin - Adrenaline.svg, epinephrine Adrenaline, also known as epinephrine, is a hormone and medication which is involved in regulating visceral functions (e.g., respiration). It appears as a white microcrystalline granule. Adrenaline is normally produced by the adrenal glands and ... References Phenylethanolamines {{Amine-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epinephrine
Adrenaline, also known as epinephrine, is a hormone and medication which is involved in regulating visceral functions (e.g., respiration). It appears as a white microcrystalline granule. Adrenaline is normally produced by the adrenal glands and by a small number of neurons in the medulla oblongata. It plays an essential role in the fight-or-flight response by increasing blood flow to muscles, heart output by acting on the SA node, pupil dilation response, and blood sugar level. It does this by binding to alpha and beta receptors. It is found in many animals, including humans, and some single-celled organisms. It has also been isolated from the plant ''Scoparia dulcis'' found in Northern Vietnam. Medical uses As a medication, it is used to treat several conditions, including allergic reaction anaphylaxis, cardiac arrest, and superficial bleeding. Inhaled adrenaline may be used to improve the symptoms of croup. It may also be used for asthma when other treatments are not e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
