5-hydroxyindole acetic acid

5-hydroxyindole acetic acid

5-HIAA A biogenic amine found especially in the brain and other organs, which accounts for 1% of degraded tryptophan; 5-HIAA may be markedly–25-50-fold normal ↑ in carcinoid tumors, especially of the midgut–less commonly of lung and ovary–features of carcinoid syndrome–eg, bronchoconstriction, diarrhea, flushing, right-sided heart lesions, facial telangiectasia; 5-HIAA is also ↑ in Hartnup's disease, nontropical sprue, in some mental conditions Drugs Acetaminophen, caffeine, l-dopa, glyceryl, guaiacolate, heparin, nicotine, phenothiazine, reserpine, salicylates; 5-HIAA is ↓ in major GI tract resection, renal insufficiency, PKU, phenothiazine therapy
References in periodicals archive ?
Diagnostic workup only yielded high 5-hydroxyindole acetic acid (5-HIAA) (71 mg/24 hours, upper limit of normal 20 mg/24 hours) and positive Indium pentetreotide (ln-111) scanning test results at that time.
It was also noted that her 24-hour urinary excretion of 5-hydroxyindole acetic acid was elevated at 95 mg (normal <6 mg/24h).