Serotonin (24 hour urine)

General Information

Serotonin Is a chemical involved in the transmission of messages between nerve cells. The test measures the amount of serotonin in the blood.

Serotonin is obtained from the amino acid tryptophan. It is produced as needed by special cells of the nervous system, mainly the brain, as well as the bronchi and gastrointestinal tract. More than 90% of serotonin in the blood is found in platelets.

Serotonin is metabolized in the liver and its metabolites, mainly 5-HIAA (5-hydroxyindoleacetic acid), are excreted in the urine.

Serotonin affects all functions of the human body - from emotions to physical activity:

• Promotes control of peristalsis;
• Regulates mood;
• Controls the sleep-wake cycle;
• Participates in blood clotting, etc.

Normally, serotonin is present in small amounts in the blood and therefore in the urine. Large amounts of serotonin and 5-HIAA can be produced continuously or some intermittently Carcinoid tumor By. Carcinoid tumors are slow-growing masses that can form in the gastrointestinal tract (especially the appendix) and lungs, although they can affect other organs as well. Serotonin produced by carcinoid tumors can cause facial redness, diarrhea, rapid heartbeat, and wheezing, especially when the tumor has spread to the liver. This group of signs and symptoms is called Carcinoid syndrome.

When should I take a serotonin test?

The test is primarily prescribed when you have symptoms that indicate carcinoid syndrome.

Some signs and symptoms include:

• Redness of the face, neck and chest (usually starts suddenly);
• The appearance of purple spots or thin mesh-like blood vessels on the nose and upper lip;
• Diarrhea, nausea, vomiting;
• Rapid heartbeat episodes;
• Wheezing, coughing, shortness of breath.

How to prepare for the test?

• Do not eat foods such as bananas, nuts, tomatoes, pineapples, grapefruits, currants, cocoa, plums, eggplants, melons, avocados and kiwis for at least 2 days before testing.
• If you are taking medicines from the class of monoamine oxidase inhibitors, you should stop taking them one week before the test under the supervision of a doctor (consult your doctor before changing the course of treatment!).
• Intake of lithium, methyldopa, morphine and reserpine may lead to a false increase in serotonin levels.