Vanillyl mandelic acid (VMA) is a chemical end product of catecholamine metabolism. It is found in urine together with homovanillic acid (HVA). In timed urine tests its quantity (concentration μg /24 h) is assessed, along with creatinine clearance, and the concentration of cortisols, catecholamines, and metanephrines. A chemical substance is any material substance used in or obtained by a process in chemistry: A chemical compound is a substance consisting of two or more chemical elements that are chemically combined in fixed proportions. ... Catecholamines are chemical compounds derived from the amino acid tyrosine. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... Homovanillic acid (HOC6H3(OCH3)CH2COOH; synonyms: 3-Methoxy-4-hydroxyphenyl acetic acid; HVA; 4-Hydroxy-3-methoxy-benzeneacetic acid; 4-Hydroxy-3-methoxyphenylacetic acid; ) is a major catecholamine metabolite. ... A urinalysis (or UA) is an array of tests performed on urine, usually used in medical diagnosis. ... In chemistry, concentration is the measure of how much of a given substance there is mixed with another substance. ... Chemical structure of creatinine. ... Cortisol is a corticosteroid hormone produced by the adrenal cortex that is involved in the response to stress; it increases blood pressure, blood sugar levels, may cause infertility in women, and suppresses the immune system. ... Catecholamines are chemical compounds derived from the amino acid tyrosine. ... A metabolite of epinephrine (created by action of catechol O-methyltransferase on epinephrine). ...

Urinary levels of vanillyl mandelic acid are raised in pheochromocytoma, a tumor of catecholamine-secreting chromaffin cells. A pheochromocytoma (also phaeochromocytoma, English spelling) is a tumor of the medulla of the adrenal glands originating in the chromaffin cells, which secretes excessive amounts of catecholamines, usually epinephrine and norepinephrine. ... Catecholamines are chemical compounds derived from the amino acid tyrosine. ... Chromaffin cells are neuroendocrine cells found in the medulla of the adrenal gland and in other ganglia of the sympathetic nervous system. ...