Two cases had incidental finding of markedly elevated homovanillic acid
(HVA) excretion in the urine.
West, "Concomitant fall in brain dopamine and homovanillic acid
in hydrocephalic rabbits," Experimental Neurology, vol.
IVIG, intravenous immunoglobulin; AMPC, amoxicillin; HVA, homovanillic acid
; ASOT, antistreptolysin O titer.
Chronic manganese overload stimulates monoamine oxidase activity, increasing dopaminergic degradation and accumulation of its metabolite, homovanillic acid
. This metabolite has been found in excessive quantities at autopsy in patients deceased with chronic hepatopathies [4-6].
In the OAT we measure both homovanillic acid
(dopamine metabolite) and vanillylmandelic acid (norepinephrine metabolite).
Four compounds (both caffeic acid hexosides (m/z 341), homovanillic acid
hexoside (m/z 343), and first dicaffeoylquinic acid isomer (m/z 515)) showed increasing trends, three compounds showed decreasing trends, and eight compounds had maximum levels at half-ripe stage.
dioica methanolic leaf extract showed the presence of cinnamic acid, coumarins, and homovanillic acid
as phenolic compounds.
The homovanillic acid
(HVA) was 26.5mg/24hr (normal 0.0-10mg/24hr) and vanillylmandelic acid (VMA) was 25.3 mg/24hr (normal 0.0-7.5mg/24hr).
Elevation of catecholamine metabolite secretions, including urinary vanillylmandelic acid (VMA), homovanillic acid
(HVA), and dopamine, occurs in as many as 90% of pediatric patients  but is generally not seen in adolescents and adults.
Ganglioneuroblastomas have a propensity for secreting catecholamines, and approximately 90-95% actively secretes vinylmandelic acid (VMA) and homovanillic acid
(HVA).5 In addition, more mature tumors may contain vasoactive intestinal peptide (VIP) producing ganglion cells.
Following ingestion, rutin forms metabolites that include 3,4-dihydroxyphenylacetic acid (3,4-DHPAA), 3,4-dihydroxytoluene (3,4-DHT), m-hydroxyphenylacetic acid (m-HPAA), 3-methoxy-4-hydroxyphenylacetic acid (homovanillic acid
, HVA) and 3,5,7,3',5'-pentahydroxyflavonol (quercetin).
The levels of Dopamine (DA) and Homovanillic acid
(HVA) in striatum were determined by Ultra-performance liquid chromatography combined with time-of-flight mass spectrometry (UPLC-ToF-MS).