4-Hydroxytryptamine

Chemical compound related to serotonin

Chemical structure of 4-Hydroxytryptamine

4-Hydroxytryptamine, also known as serotonin, is a monoamine neurotransmitter that plays a crucial role in the central nervous system and the gastrointestinal tract of humans and other animals. It is a derivative of tryptophan, an essential amino acid.

Biochemistry

4-Hydroxytryptamine is synthesized from the amino acid L-tryptophan in a two-step process. The first step involves the hydroxylation of tryptophan to form 5-hydroxytryptophan, catalyzed by the enzyme tryptophan hydroxylase. The second step is the decarboxylation of 5-hydroxytryptophan to form serotonin, catalyzed by the enzyme aromatic L-amino acid decarboxylase.

In the body, serotonin is primarily found in the gastrointestinal tract, blood platelets, and the central nervous system. It is well known for its role in modulating mood, cognition, reward, learning, memory, and numerous physiological processes such as vomiting and vasoconstriction.

Physiological Functions

Serotonin is involved in the regulation of several key functions:

• Mood Regulation: It is often referred to as the "feel-good" neurotransmitter because of its role in mood stabilization and feelings of well-being and happiness.
• Sleep: Serotonin is a precursor to melatonin, a hormone that regulates sleep-wake cycles.
• Appetite: It helps regulate appetite and digestion.
• Blood Clotting: Serotonin is stored in platelets and released during blood clotting, contributing to hemostasis.
• Bone Density: It plays a role in maintaining bone density.

Receptors

Serotonin exerts its effects by binding to serotonin receptors, which are found throughout the body. There are several types of serotonin receptors, classified into seven families (5-HT1 to 5-HT7), each with subtypes. These receptors are involved in various physiological processes and are targets for many pharmacological agents.

Clinical Significance

Serotonin is implicated in a variety of psychiatric disorders, including depression, anxiety disorders, and schizophrenia. Many antidepressants, such as selective serotonin reuptake inhibitors (SSRIs), function by increasing serotonin levels in the brain.

Additionally, serotonin syndrome is a potentially life-threatening condition caused by excessive accumulation of serotonin, often due to drug interactions or overdose.

Related pages

• Serotonin receptor
• Selective serotonin reuptake inhibitor
• Tryptophan
• Neurotransmitter