WHAT IS SEROTONIN (5-HYDROXYTRYPTAMINE) TEST?
Serotonin is an indolamine synthesized from L-tryptophan, an essential amino acid, by the argentaffin cells of the intestinal mucosa. Serotonin is stored in and transported by platelets, but it is also found in many body tissues, including the central nervous system and gastrointestinal tract. Serotonin mediates cardiovascular integrity, neurotransmission, smooth muscle contraction (gastrointestinal motility), prolactin release, and growth hormone release and functions in thermocoagulation. This broad array of actions occurs as a result of the location of serotonin receptors throughout the body. This test is used to confirm the diagnosis of carcinoid tumours, in which the highest increases in levels are found.