Urinalysis and Body Fluids 6th Edition by Majorie DiLorenzo, Susan Strasinger

Exercise 17

5-HIAA is a degradation product of:

A. Heme

B. Indole

C. Serotonin

D. Melanin

Step 1 of 2

5-HIAA: (5-hydroxyindoleacetic acid)

It is a degradation substance of serotonin, which is excreted in urine in small volume.

• Serotonin is formed from tryptophan by the intestinal arginine cells, and carried by platelets throughout the body

• Generally, the body uses almost all serotonin, but when carcinoid tumors associated with argentaffin cell develops, serotonin is produced that leads to high 5-HIAA in urine

Therefore, 5-HIAA is degradation substance of “serotonin”. Hence, the correct answer is option.