A substance found in many tissues, particularly blood platelets, the digestive tract lining, and the brain.
Serotonin is released from platelets at the site of bleeding, where it constricts small blood vessels, reducing blood loss.
In the digestive tract, it inhibits gastric secretion and stimulates smooth muscle of the intestine.
In the brain, where it acts as a neurotransmitter, levels are reduced in people who are depressed; certain antidepressants raise the level.
Serotonin agonists are used to block its effects in acute migraine attacks.
Also known as 5-hydroxytryptamine, this is a substance widely distributed in the body tissue, but especially in the PLATELETS in the blood, the lining of the gastrointestinal tract, and the BRAIN. Serotonin is believed to have a similar function to that of HISTAMINE in INFLAMMATION. In the gut it inhibits gastric secretion and stimulates smooth (involuntary) muscle in the walls of the INTESTINE. Serotonin participates in the transmission of nerve impulses and may have a function in controlling mood and states of consciousness. (See also SELECTIVE SEROTONIN-REUPTAKE INHIBITORS (SSRIS).)
(5-hydroxytryptamine) n. a compound widely distributed in the tissues, particularly in the blood platelets, intestinal wall, and central nervous system. Serotonin is thought to play a role in inflammation similar to that of *histamine and it is involved in the genesis of a migrainous headache. Drugs that act like serotonin are used in the treatment of migraine (see 5HT1 agonist). It also acts as a *neurotransmitter, and its levels in the brain are believed to have an important influence on mood. Drugs that prolong its effects are used as antidepressants (see SNRI; SSRI).
These ANTIDEPRESSANT DRUGS have few antimuscarinic effects (see ANTIMUSCARINE), but do have adverse effects of their own – predominantly gastrointestinal. They are, however, much safer in overdose than the tricyclic antidepressants, which is a major advantage in patients who are potentially suicidal. Examples are citalopram, used to treat panic disorders, as well as depressive illness; FLUOXETINE; and PAROXETINE. (See also MENTAL ILLNESS.)... selective serotonin-reuptake inhibitors (ssris)
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