Adrenaline, Capsaicin, Neurochemistry, Vanilla, Vanillyl Group, Women
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Homovanillic acid (HVC) and Vanillylmandelic acid (VMA)

Homovanillic acid (HVA) is a major catecholamine metabolite that is produced by a consecutive action of monoamine oxidase and catechol-O-methyltransferase on dopamine.

Homovanillic acid is used as a reagent to detect oxidative enzymes, and is associated with dopamine levels in the brain.

In psychiatry and neuroscience, brain and cerebrospinal fluid levels of HVA are measured as a marker of metabolic stress caused by 2-deoxy-D-glucose.

  • Marcelis M, Suckling J, Hofman P, Woodruff P, Bullmore E, van Os J (September 2006). “Evidence that brain tissue volumes are associated with HVA reactivity to metabolic stress in schizophrenia”. Schizophr. Res. 86 (1–3): 45–53. doi:10.1016/j.schres.2006.05.001. PMID 16806836

HVA presence supports a diagnosis of neuroblastoma and malignant pheochromocytoma.

Fasting plasma levels of HVA are known to be higher in females than in males.[citation needed] This does not seem to be influenced by adult hormonal changes, as the pattern is retained in the elderly and post-menopausal as well as transgender people according to their genetic sex, both before and during cross-sex hormone administration.

Differences in HVA have also been correlated to tobacco usage, with smokers showing significantly lower amounts of plasma HVA.

Vanillylmandelic acid (VMA)

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.

Norepinephrine degradation. Vanillylmandelic acid is shown at top right. Enzymes are shown in boxes. Figure 11-4 in: Rod Flower; Humphrey P. Rang; Maureen M. Dale; Ritter, James M. (2007). Rang & Dale’s pharmacology. Edinburgh: Churchill Livingstone. ISBN 978-0-443-06911-6

Clinical significance

Urinary VMA is elevated in patients with tumors that secrete catecholamines.

These urinalysis tests are used to diagnose an adrenal gland tumor called pheochromocytoma, a tumor of catecholamine-secreting chromaffin cells. These tests may also be used to diagnose neuroblastomas, and to monitor treatment of these conditions.

Norepinephrine is metabolised into normetanephrine and VMA. Norepinephrine is one of the hormones produced by the adrenal glands, which are found on top of the kidneys. These hormones are released into the blood during times of physical or emotional stress, which are factors that may skew the results of the test.[citation needed]

See also

References

  1. Lambert, G.W.; Eisenhofer, G.; Jennings, G.L.; Esler, M.D. (1993). “Regional homovanillic acid production in humans”. Life Sciences. 53 (1): 63–75. doi:10.1016/0024-3205(93)90612-7. PMID 8515683.
  2. Marcelis M, Suckling J, Hofman P, Woodruff P, Bullmore E, van Os J (September 2006). “Evidence that brain tissue volumes are associated with HVA reactivity to metabolic stress in schizophrenia”. Schizophr. Res. 86 (1–3): 45–53. doi:10.1016/j.schres.2006.05.001. PMID 16806836.
  3. Giltay E, Kho K, Blandjaar B, Verbeek M, Geurtz P, Geleijnse J, Gooren L (July 2005). “The sex difference of plasma homovanillic acid is unaffected by cross-sex hormone administration in transgender people”. J Endocrinol. 187 (1): 109–16. doi:10.1677/joe.1.06307. hdl:2066/47682. PMID 16214946. Archived from the original on 2011-02-27. Retrieved 2011-01-30.
  4. Fatiadi, Alexander; Schaffer, Robert (1974). “An Improved Procedure for Synthesis of DL-4-Hydroxy-3-methoxymandelic Acid (DL-“Vanillyl”-mandelic Acid, VMA)” (PDF). Journal of Research of the National Bureau of Standards Section A. 78A (3): 411–412. doi:10.6028/jres.078A.024. PMC 6742820. PMID 32189791. Retrieved 19 December 2013.
  5. Figure 11-4 in: Rod Flower; Humphrey P. Rang; Maureen M. Dale; Ritter, James M. (2007). Rang & Dale’s pharmacology. Edinburgh: Churchill Livingstone. ISBN 978-0-443-06911-6.
  6. Magera MJ, Thompson AL, Matern D, Rinaldo P (May 2003). “Liquid chromatography-tandem mass spectrometry method for the determination of vanillylmandelic acid in urine”. Clin. Chem. 49 (5): 825–6. doi:10.1373/49.5.825. PMID 12709381.
Neurotransmitter metabolic intermediates
Tumor markers

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