homovanillic acid การใช้

• Both of these substances are degraded to form homovanillic acid ( HVA ).
• A difficulty in this approach however, is separating the high level of plasma homovanillic acid contributed by the metabolism of norepinephrine.
• In clinical research on schizophrenia, measurements of homovanillic acid in plasma have been used to estimate levels of dopamine activity in the brain.
• "' Homovanillic acid "'( "'HVA "') is a major catecholamine metabolite and is produced by the consecutive action of monoamine oxidase and catechol-O-methyl transferase on dopamine.
• Furthermore, decreased levels of homovanillic acid, altered response to dextroamphetamine, responses of depressive symptoms to dopamine receptor agonists, decreased dopamine receptor D1 binding in the striatum, and polymorphism of dopamine receptor genes implicate dopamine in depression.
• Carbidopa reduces the amount of levodopa required to produce a given response by about 75 % and, when administered with levodopa, increases both plasma levels and the plasma half-life of levodopa, and decreases plasma and urinary dopamine and homovanillic acid.
• Similarly in the study, the legs were the most common affected part of the body and the attacks were reported as stiffening and cramps by those affected . During an episode of PED patients find walking nearly impossible . Cerebral spinal fluid ( CSF ) analysis showed a two-fold increase of homovanillic acid and 5-hydroxyindoleacetic acid immediately following exercise compared to normal levels.
• "' 3-Methoxytyramine "'( "'3-MT "'), also known as "'3-methoxy-4-hydroxyphenethylamine "', is a metabolite of the neurotransmitter dopamine 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.