5-HT receptors, 5-hydroxytryptamine receptors, or serotonin receptors, are a group of G protein-coupled receptor and ligand-gated ion channels found in the central and peripheral nervous systems. They mediate both excitatory and inhibitory neurotransmission. The serotonin receptors are activated by the neurotransmitter serotonin, which acts as their natural ligand.
Triptans are a family of tryptamine-based drugs used as abortive medication in the treatment of migraines and cluster headaches. This drug class was first commercially introduced in the 1990s. While effective at treating individual headaches, they do not provide preventive treatment and are not considered a cure. They are not effective for the treatment of tension–type headache, except in persons who also experience migraines. Triptans do not relieve other kinds of pain.
Pindolol, sold under the brand name Visken among others, is a nonselective beta blocker which is used in the treatment of hypertension. It is also an antagonist of the serotonin 5-HT1A receptor, preferentially blocking inhibitory 5-HT1A autoreceptors, and has been researched as an add-on therapy to various antidepressants, such as clomipramine and the selective serotonin reuptake inhibitors (SSRIs), in the treatment of depression and obsessive-compulsive disorder.
Methysergide, sold under the brand names Deseril and Sansert, is a monoaminergic medication of the ergoline and lysergamide groups which is used in the prophylaxis and treatment of migraine and cluster headaches. It has been withdrawn from the market in the United States and Canada due to adverse effects. It is taken by mouth.
The 5-HT2 receptors are a subfamily of 5-HT receptors that bind the endogenous neurotransmitter serotonin (5-hydroxytryptamine, 5-HT). The 5-HT2 subfamily consists of three G protein-coupled receptors (GPCRs) which are coupled to Gq/G11 and mediate excitatory neurotransmission, including 5-HT2A, 5-HT2B, and 5-HT2C. For more information, please see the respective main articles of the individual subtypes:
5-Methoxytryptamine (5-MT), also known as mexamine, is a tryptamine derivative closely related to the neurotransmitters serotonin and melatonin. 5-MT has been shown to occur naturally in the body in low levels. It is biosynthesized via the deacetylation of melatonin in the pineal gland.
The serotonin 1A receptor is a subtype of serotonin receptors, or 5-HT receptors, that binds serotonin, also known as 5-HT, a neurotransmitter. 5-HT1A is expressed in the brain, spleen, and neonatal kidney. It is a G protein-coupled receptor (GPCR), coupled to the Gi protein, and its activation in the brain mediates hyperpolarization and reduction of firing rate of the postsynaptic neuron. In humans, the serotonin 1A receptor is encoded by the HTR1A gene.
5-hydroxytryptamine receptor 1B also known as the 5-HT1B receptor is a protein that in humans is encoded by the HTR1B gene. The 5-HT1B receptor is a 5-HT receptor subtype.
5-hydroxytryptamine (serotonin) receptor 1D, also known as HTR1D, is a 5-HT receptor, but also denotes the human gene encoding it. 5-HT1D acts on the central nervous system, and affects locomotion and anxiety. It also induces vasoconstriction in the brain.
5-hydroxytryptamine (serotonin) 1E receptor (5-HT1E) is a highly expressed human G-protein coupled receptor that belongs to the 5-HT1 receptor family. The human gene is denoted as HTR1E.
5-hydroxytryptamine (serotonin) receptor 1F, also known as HTR1F is a 5-HT1 receptor protein and also denotes the human gene encoding it.
5-Hydroxytryptamine (serotonin) receptor 5A, also known as HTR5A, is a protein that in humans is encoded by the HTR5A gene. Agonists and antagonists for 5-HT receptors, as well as serotonin uptake inhibitors, present promnesic (memory-promoting) and/or anti-amnesic effects under different conditions, and 5-HT receptors are also associated with neural changes.
5-Carboxamidotryptamine (5-CT) is a tryptamine derivative closely related to the neurotransmitter serotonin.
BRL-15,572 is a drug which acts as a selective antagonist for the serotonin receptor subtype 5-HT1D, with around 60x selectivity over other related receptors. The 5-HT1D receptor has a very similar pharmacology to the closely related 5-HT1B receptor, and most older ligands for these receptors bind to both subtypes with approximately equal affinity, so development of compounds such as BRL-15572 which are able to selectively block the 5-HT1D subtype while leaving 5-HT1B unaffected, have been a significant advance which has helped scientists in researching the function of these serotonin receptor subtypes. One function of the 5-HT1D receptor this research has revealed is its role in modulating release of the neurotransmitter glutamate in the brain, as well as functions in regulation of cerebral blood pressure which are important in the pathogenesis of migraine headaches.
GR-127935 is a drug which acts as a selective antagonist at the serotonin receptors 5-HT1B and 5-HT1D. It has little effect when given by itself but blocks the antiaggressive effect of 5-HT1B agonists, and alters release of serotonin in the brain, as well as reducing drug-seeking behaviour in cocaine addicted rats.
CGS-12066A is a drug which acts as a potent and selective agonist for the 5-HT1B receptor with lower affinity for the three 5-HT2 receptor subtypes. It is used for studying the role of the 5-HT1B receptor in various processes including perception of pain and the sleep-wake cycle.
Roxindole (EMD-49,980) is a dopaminergic and serotonergic drug which was originally developed by Merck KGaA for the treatment of schizophrenia. In clinical trials its antipsychotic efficacy was only modest but it was unexpectedly found to produce potent and rapid antidepressant and anxiolytic effects. As a result, roxindole was further researched for the treatment of depression instead. It has also been investigated as a therapy for Parkinson's disease and prolactinoma.
1-(1-Naphthyl)piperazine (1-NP) is a drug which is a phenylpiperazine derivative. It acts as a non-selective, mixed serotonergic agent, exerting partial agonism at the 5-HT1A, 5-HT1B, 5-HT1D, 5-HT1E, and 5-HT1F receptors, while antagonizing the 5-HT2A, 5-HT2B, and 5-HT2C receptors. It has also been shown to possess high affinity for the 5-HT3, 5-HT5A, 5-HT6, and 5-HT7 receptors, and may bind to 5-HT4 and the SERT as well. In animals it produces effects including hyperphagia, hyperactivity, and anxiolysis, of which are all likely mediated predominantly or fully by blockade of the 5-HT2C receptor.
Indorenate (TR-3369), is a tryptamine derivative which acts as an agonist at the 5-HT1A, 5-HT1B and 5-HT2C serotonin receptors. It has anxiolytic, antihypertensive and anorectic effects, predominantly through action at 5-HT1A, but with some contribution from the 5-HT1B and 5-HT2C subtypes, and possibly some other non-serotonergic targets also.
LY-393558 is a potent serotonin reuptake inhibitor and antagonist of the 5-HT1B, 5-HT1D, and 5-HT2A receptors. LY-393558 was also found to reduce serotonin-induced vasoconstriction, indicating that it may have therapeutic potential for the treatment of pulmonary hypertension.
