Health Effects of Serotonin
Serotonin is a neurotransmitter/hormone which helps in transmitting nerve impulses in our body. Serotonin is believed to be keeping our moods in control by enabling deep sleep, calming anxiety and relieving depression. It also assists in developing memory as well as learning abilities. In humans, serotonin levels regulate appetite– increase in serotonin levels give a feeling of satiety and decrease appetite.
Serotonin is synthesized from the amino acid, Tryptophan. It is secreted by the enterochromaffin cells which line the walls of the digestive tract. Presence of food in the digestive tract triggers the release of serotonin from the enterochromaffin cells. Blood platelets present in the veins of the gut absorb the excess serotonin. Increased level of serotonin is known to have adverse effects on humans. An increase in gut serotonin level causes diarrhea and nausea. Also, an increase in blood serotonin levels causes low bone density. Serotonin acts as a growth factor for certain cell types. Optimum level of serotonin in the body assists in rapid growth of cells thereby assisting in healing wounds, repairing liver damages and maintaining bone mass. However, a sudden increase in serotonin levels causes pain, which justifies the presence of serotonin in insect venoms. High levels of serotonin can constrict the blood vessels, thus causing blood clots in case of injury or insect bite.
Role of Serotonin
Being a neurotransmitter, serotonin plays a vital role in our life. It closely controls our physical and psychological behavior. It influences the brain cells and regulates our moods, appetite, sexual desire, memory and reasoning. The heart and network of blood vessels are greatly dependent on serotonin levels for their proper functioning. Low levels of serotonin often cause anxiety, mild to moderate depression, fatigue, insomnia and general mood swings.
Serotonin and Depression
Since low levels of serotonin cause depression, antidepressants work on the principle of effectively altering the levels of blood serotonin levels, thereby boosting the mood. Tianeptine, a powerful antidepressant drug, is a known for its effects in elevating mood and giving a feeling of wellness. However, intake of antidepressants needs to be carefully monitored. Undesired increase in serotonin levels decreases the bone density making the patient vulnerable to osteoporosis.
Hyperserotonemia or Serotonin Syndrome is a life threatening condition caused by the presence of excessive levels of serotonin in the body. Overdose of a combination of antidepressant drugs are usually held responsible for this drug reaction. Combining migraine medicines with antidepressants usually shoot the levels of serotonin out of control, often causing agitation, nausea and loss of coordination. Muscle spasm, unreasonable change in blood pressure and increase in body temperature are some other symptoms indicating Hyperserotonemia.
Discontinuing the medicines that caused the syndrome and treatment with Cyproheptadine effectively stabilizes the serotonin levels. Cyproheptadine is an antiserotonergic agent and works by blocking serotonin synthesis in the body.