Serotonin and agents that act primarily on serotonergic processes

Serotonin, or 5-hydroxytryptamine, belongs to the group of indolylalkylamines in chemical structure. It is a biogenic amine formed in the body as a result of hydroxylation of the amino acid L-tryptophan.
Serotonin is found in various organs and tissues, including thrombocytes, enterochromaffine cells of the intestine, and cells of the medulla of the adrenal glands. In the nervous system, the biosynthesis of serotonin occurs in the cytoplasm of nerve endings. It accumulates in synaptic vesicles, is released under the influence of nerve impulses and interacts with specific receptors, denoted as serotonin (serotonergic). Serotonin receptors are also found in peripheral tissues.
In the past, serotonin receptors were divided into M-receptors blocked by morphine, and D-receptors blocked by phenoxybenzamine. Currently, another classification of these receptors has been adopted, according to which their main subtypes are 5-HT M 1 (5HT M1 - from the words 5-Hydróxy Tryptophan, S - from Serotonine) (or S M1) -receptors, 5-HT M2 (or S M2) receptors, 5-HT3 (or S3) -receptors.
5-HT M2-Receptors are contained in the smooth muscles of the walls of blood vessels, in bronchi and platelets. 5-HT M1-Receptors may be contained in the smooth muscle of the gastrointestinal tract. 5-HT M3-Receptors are found in peripheral tissues and in the central nervous system.
The pharmacological effects of serotonin correlate mainly with the excitation of 5-HT M, 2 receptors.
The physiological role of serotonin has not been adequately studied. In the central nervous system he plays the role of a mediator. With the influence on serotonin biosynthesis, its metabolism and interaction with receptors, the mechanism of action of a number of psychotropic drugs is associated. A major role is attached to the role of serotonin in the pathogenesis of depression and the mechanism of action of antidepressants (see).
It is believed that the development of nausea and vomiting can be due to the stimulation of serotonin 5-HT M3 receptors localized in the vomiting center area.
Peripheral action of serotonin is characterized by contraction of smooth muscles of the uterus, intestines, bronchi and other smooth muscle organs, narrowing of blood vessels. He is one of the mediators of inflammation; Has a pronounced edematous effect with local (intradermal, subcutaneous) application. It has the ability to shorten bleeding time, increase the number of platelets in peripheral blood, and increase aggregation of thrombocytes. When platelets are aggregated, serotonin is released from them.
As drugs, serotonin and some of its derivatives have been used, as well as some of its antagonists.