Description
5-HIAA is the major product of the oxidative de-amination of serotonin, a derivative of the amino acid tryptophan. Serotonin is a potent muscle stimulant and vasoconstrictor that is formed in the enterochromaffin c cells of the gastrointestinal tract. Thus, 5-HIAA levels reflect serotonin synthesis. See Also 5-Hydroxytryptophan , and Serotonin
Indications
5-HIAA levels are increased in metastatic carcinoid tumours. High 5-HIAA levels are associated with midgut carcinoids, while slight elevations are associated with non-tropical sprue. Decreased levels are found in phenylketonuria, renal insufficiency, depression and small intestine resection.
Sample Type, Quantity & Conditions
30 ml of 24 Hrs urine
Special Precautions
State 24 Hrs urine volume. Adjust pH to (3-6) with Hydrochloric Acid.
Normal Range
< 15.0 mg/24 Hrs < 78.45 nmol/ 24Hrs
