Serotonin

Serotonin
Names
	IUPAC name 5-Hydroxytryptamine
	Preferred IUPAC name 3-(2-Aminoethyl)-1H-indol-5-ol
	Other names 5-Hydroxytryptamine, 5-HT, Enteramine; Thrombocytin, 3-(β-Aminoethyl)-5-hydroxyindole, 3-(2-Aminoethyl)indol-5-ol, Thrombotonin
Identifiers
CAS Number	50-67-9 ;
3D model (JSmol)	Interactive image;
ChEBI	CHEBI:28790 ;
ChEMBL	ChEMBL39 ;
ChemSpider	5013 ;
ECHA InfoCard	100.000.054
IUPHAR/BPS	5;
KEGG	C00780 ;
MeSH	Serotonin
PubChem CID	5202;
UNII	333DO1RDJY ;
CompTox Dashboard (EPA)	DTXSID8075330 ;
	InChI InChI=1S/C10H12N2O/c11-4-3-7-6-12-10-2-1-8(13)5-9(7)10/h1-2,5-6,12-13H,3-4,11H2 Key: QZAYGJVTTNCVMB-UHFFFAOYSA-N ; InChI=1/C10H12N2O/c11-4-3-7-6-12-10-2-1-8(13)5-9(7)10/h1-2,5-6,12-13H,3-4,11H2 Key: QZAYGJVTTNCVMB-UHFFFAOYAX;
	SMILES C1=CC2=C(C=C1O)C(=CN2)CCN;
Properties
Chemical formula	C10H12N2O
Molar mass	176.215 g/mol
Appearance	White powder
Melting point	167.7 °C (333.9 °F; 440.8 K) 121–122 °C (ligroin)
Boiling point	416 ± 30 °C (at 760 Torr)
Solubility in water	slightly soluble
Acidity (pKa)	10.16 in water at 23.5 °C
Dipole moment	2.98 D
Hazards
	Lethal dose or concentration (LD, LC):
LD50 (median dose)	750 mg/kg (subcutaneous, rat), 4500 mg/kg (intraperitoneal, rat), 60 mg/kg (oral, rat)
Safety data sheet (SDS)	External MSDS
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Serotonin
Clinical data
Other names	5-HT, 5-Hydroxytryptamine, Enteramine, Thrombocytin, 3-(β-Aminoethyl)-5-hydroxyl solution , Thrombotonin
Physiological data
Source tissues	raphe nuclei, enterochromaffin cells
Target tissues	system-wide
Receptors	5-HT1, 5-HT2, 5-HT3, 5-HT4, 5-HT5, 5-HT6, 5-HT7
Agonists	Indirectly: SSRIs, MAOIs
Precursor	5-HTP
Biosynthesis	Aromatic L-amino acid decarboxylase
Metabolism	MAO
Identifiers
	IUPAC name 3-(2-Aminoethyl)-1H-indol-5-ol;
CAS Number	50-67-9;
PubChem CID	5202;
IUPHAR/BPS	5;
ChemSpider	5013;
KEGG	C00780;
PDB ligand	SRO (PDBe, RCSB PDB);
CompTox Dashboard (EPA)	DTXSID8075330 ;
ECHA InfoCard	100.000.054

Serotonin (/ˌsɛrəˈtoʊnɪn, ˌsɪərə-/), also known as 5-hydroxytryptamine (5-HT), is a monoamine neurotransmitter with a wide range of functions in both the central nervous system (CNS) and also peripheral tissues. It is involved in mood, cognition, reward, learning, memory, and physiological processes such as vomiting and vasoconstriction. In the CNS, serotonin regulates mood, appetite, and sleep.

Most of the body's serotonin—about 90%—is synthesized in the gastrointestinal tract by enterochromaffin cells, where it regulates intestinal movements. It is also produced in smaller amounts in the brainstem's raphe nuclei, the skin's Merkel cells, pulmonary neuroendocrine cells, and taste receptor cells of the tongue. Once secreted, serotonin is taken up by platelets in the blood, which release it during clotting to promote vasoconstriction and platelet aggregation. Around 8% of the body's serotonin is stored in platelets, and 1–2% is found in the CNS.

Serotonin acts as both a vasoconstrictor and vasodilator depending on concentration and context, influencing hemostasis and blood pressure regulation. It plays a role in stimulating myenteric neurons and enhancing gastrointestinal motility through uptake and release cycles in platelets and surrounding tissue. Biochemically, serotonin is an indoleamine synthesized from tryptophan and metabolized primarily in the liver to 5-hydroxyindoleacetic acid (5-HIAA).

Serotonin is targeted by several classes of antidepressants, including selective serotonin reuptake inhibitors (SSRIs) and serotonin–norepinephrine reuptake inhibitors (SNRIs), which block reabsorption in the synapse to elevate its levels. It is found in nearly all bilateral animals, including insects, spiders and worms, and also occurs in fungi and plants. In plants and insect venom, it serves a defensive function by inducing pain. Serotonin released by pathogenic amoebae may cause diarrhea in the human gut, while its presence in seeds and fruits is thought to stimulate digestion and facilitate seed dispersal.