A simple and accurate method for the determination of urinary 3-methoxy-4-hydroxy-mandelic acid, vanillyl-mandelic acid (VMA), is described. The separation of VMA from all other phenolic acids in approximately 0.05 ml. untreated urine is achieved by using low-voltage paper electrophoresis with different buffer concentrations for the cathode and the anode. The concentration of the electrophoreti...

BACKGROUND: The monoamine acids 5’-hydroxyindoleacetic (HIAA), homovanillic (HVA), and vanillylmandelic (VMA) are metabolites of serotonin and the catecholamine neurotransmitters epinephrine, norepinephrine, and dopamine. Laboratory measurement of these acids in urine is used to assess overproduction of the parent amines due to carcinoid and neuroendocrine tumors (neuroblastoma, pheochromocytom...

This study characterizes the diurnal profiles of ten melatonin synthesis-related indoles, the quantitative relations between these compounds, and daily variations in the contents of catecholamines and their metabolites in the domestic duck pineal organ. Fourteen-week-old birds, which were reared under a 12L:12D cycle, were killed at two-hour intervals. The indole contents were measured using HP...

We report the biochemical hallmarks of tyrosine hydroxylase deficiency with emphasis on reliable diagnostic strategies of four new cases of an inborn error of tyrosine hydroxylase (TH). Three of our patients from different parts of the Netherlands were found homozygous for a mutation in exon 6 (G698A) of the TH gene, and one patient was found compound heterozygous for the same mutation and an a...

Measurement of urinary xanthurenic acid (XA) has been used clinically to study a variety of disorders caused by vitamin B6 deficiency. To obviate some cumbersome steps of current methods for measuring XA in human urine, we have developed a simple fluorometric method. We apply the urine sample to a solid-phase extraction column containing trimethylaminopropyl group bound to silica, which enables...

To separately measure vanillylmandelic acid (VMA) and homovanillic acid (HVA) in urine, the sample is diluted 10-fold with 50 mmol/L phosphoric acid, then exactly 5 microL is injected directly onto a 50 X 4.6 mm column of Nucleosil 3C18. Samples can be injected at 5-min intervals because all peaks after these compounds of interest are washed away. VMA is eluted from the column after 2.8 min wit...

Objective: Monoamine neurotransmitters have been considered important mediators of schizophrenia pathology and antipsychotic drug action. This study examines the level of monoamine metabolites, homovanillic acid (HVA), 5-hydroxy indole acetic acid (5-HIAA), and vanillylmandelic acid (VMA), monoamine metabolites of major neurotransmitters dopamine, serotonin and norepinephrine, respectively in u...

A sensitive and easy analytical method for catecholamine metabolites including 4-hydroxy-3-methoxyphenylglycol sulfate (HMPG sulfate), vanillylmandelic acid (VMA) and homovanillic acid (HVA) determination was developed based on liquid chromatography-tandem mass spectrometry in a negative multiple reaction monitoring mode. The analytes were rapidly separated on a reversed-phase Waters Xbridge C1...

A 42-yr-old female, mother of five children, was referred to this institution for further evaluation of recurrent episodes of severe arterial hypertension. Blood pressures taken on several occasions during the past 3 yr by her general practitioner had documented recurrent hypertensive crises with systolic/diastolic measurements of up to 300/145 mm Hg. These episodes were frequently accompanied ...