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5-hydroxyindoleacetic acid

a product of serotonin metabolism excreted in large amounts in patients with carcinoid tumors. Abbreviated 5-HIAA.

5-hydroxyindoleacetic acid (5-HIAA)

an acid produced by serotonin metabolism, measured in the blood and urine to aid in the diagnosis of certain kinds of tumors. It commonly rises above normal levels in whole blood in association with asthma, diarrhea, rapid heartbeat, and other symptoms and is elevated in the urine of patients with carcinoid syndrome. Its normal concentration in whole blood is 0.05 to 0.20 g/mL; its normal accumulation in urine after 24-hour collection is 1 to 5 mg.


5-Hydroxy-indoleacetic acid, see there.


5-hydroxyindoleacetic acid.
References in periodicals archive ?
The double-blind TELECAST study enrolled 76 patients with or without concomitant SSA therapy provided they qualified based on at least one sign/symptom of carcinoid syndrome, such as at least two episodes of flushing per day, elevated urinary 5-HIAA at baseline, or nausea present on at least one out of five days at baseline.
A subsequent serum chromogranin A was elevated at 52 ng/ml (reference normal <34 ng/ml) and a 24-hour urine 5-HIAA was elevated at 15 mg/24 hrs (reference range 0-6 mg/24 hrs).
METHODS: Cortisol and 5-HIAA acid levels were measured by commercial enzyme-linked immunosorbent assay kits.
Sample contents of 5-HT, Trp and 5-HIAA were determined using an HPLC electrochemical detection technique.
Clinically we could have measured serum peptide YY but this test is not available in our institute and we did not measure serum 5-HIAA as the patient did not present with symptoms suggestive of carcinoid syndrome.
Symptom improvement was greatest for those receiving high-dose LX1031 who had at least a 15% reduction in 5-HIAA levels, according to Dr.
While the 5-HIAA levels were related to impulsivity, the CSF testosterone levels were related to aggressiveness and interpersonal violence.
However, foregut carcinoids, which include bronchial carcinoids as well do not have increased 5-HIAA levels, as was also seen in our study.
Some of these studies found a correlation between 5-HIAA levels in the fluid bathing the brain (i.
Serial CTs over the next few years revealed no change in the two liver masses, and annual urinary 5-HIAA levels remained within the normal range.