Serotonin and carcinoid tumors

Serotonin is produced from tryptophan and is predominately found in the digestive system. This essential amino acid can’t be produced by the body itself and must enter the body through the consumption of foods that are rich in tryptophan. Typical examples of such foods include red meat, cheese and various nuts. There is a direct correlation between the amount of tryptophan and the levels of serotonin, where a deficiency in tryptophan can result in the significant lowering of serotonin levels.

The main functions of serotonin is to transmit impulses and also to constrict blood vessels, this process is instrumental in the wake-sleep cycle and if it is disrupted then it can have a large impact on the mood of an individual. This can impact many parts of the body, ranging from motors skills to various emotions. Serotonin is regarded as a natural mood stabiliser and can be involved in a number of different process such as regulating anxiety, helping to heal wounds, reducing depression, maintaining healthy bones and stimulating nausea.

Serotonin test

The expected normal range for serotonin concentration within the human blood can be between 100-300 ng/mL. This figure can be largely dependent on what samples are being tested and what is actually being analysed. Elevated levels of serotonin can be an indicator of carcinoid syndrome, this encompasses a group of symptoms that can be associated to tumors of the small intestine, bronchial tubes, colon and appendix. The general symptoms of carcinoid tumors include rapid heart rate, flushing of the face, wheezing and diarrhoea. A simple blood test can be undertaken in order for diagnosis of the disease or even rule it out.

Serotonin test is usually required, which tends to be followed up by a 24 hour urine 5-HIAA test in order to aid the diagnosis of carcinoid tumors. The detection of elevated levels of serotonin in patients who display symptoms of carcinoid syndrome can be regarded as suggestive but not definite diagnostic of carcinoid tumors. In order to diagnose the condition the tumor needs to be isolated and then biopsied. There have also been cases where patients have the symptoms of carcinoid tumor but the levels of serotonin and 5-HIAA have come back as normal. In these situations it is possible for the tumor to not secrete serotonin or it could be secreting it intermittently. However, a patients that has normal levels of serotonin and 5-HIAA, showing no signs of any symptoms is unlikely to contain any serotonin secreting carcinoid tumors.

Treatment of serotonin deficiency

Anti-depressant medication such as selective serotonin reuptake inhibitors (SSRIs) can be used in order to facilitate the body to be able to utilise the serotonin more efficiently. These medication works by allowing more serotonin to be present in circulation throughout the brain by inhibiting the brain from reabsorbing it. Some of the most common SSRIs include Prozac, Celexa, Paxil, Lexapro and Zoloft.

Just like many other medication, these do not always work on everyone. Also, in some cases these medications might result in a wide range of side effects. If SSRIs are not a viable option then the natural remedies approach needs to be undertaken. Such as doing physical exercise, consuming more serotonin boosting foods in your diet, intentionally creating a happy mood by doing or thinking of things that make you happy and finally many studies have found that exposing to bright light either from the light box or the sun can result in elevating levels of serotonin in the brain.

Final thoughts

Mental and physical health can be effected if there is a deficiency in the levels of serotonin. There are many question still unanswered regarding how serotonin functions in the brain or the rest of the human body.