5-Hydroxytryptamine 1B receptor (IPR002147)
Short name: 5HT1B_rcpt
Overlapping homologous superfamilies
5-hydroxytryptamine (5-HT) or serotonin, is a neurotransmitter that it is primarily found in the gastrointestinal (GI) tract, platelets, and in the central nervous system (CNS). It is implicated in a vast array of physiological and pathophysiological pathways. Receptors for 5-HT mediate both excitatory and inhibitory neurotransmission, and modulate the release of many neurotransmitters including glutamate, GABA, dopamine, epinephrine/norepinephrine, and acetylcholine, as well as many hormones, including oxytocin, prolactin, vasopressin and cortisol. In the CNS, 5-HT receptors can influence various neurological processes, such as aggression, anxiety and appetite and, as a, result are the target of a variety of pharmaceutical drugs, including many antidepressants, antipsychotics and anorectics [PMID: 18476671].
The 5-HT receptors are grouped into a number of distinct subtypes, classified according to their antagonist susceptibilities and their affinities for 5-HT. With the exception of the 5-HT3 receptor, which is a ligand-gated ion channel [PMID: 11989819], all 5-HT receptors are members of the rhodopsin-like G protein-coupled receptor family [PMID: 18476671], and they activate an intracellular second messenger cascade to produce their responses.
The 5-HT1 receptors are a subfamily of 5-HT receptors that were originally classified according to their inhibition of adenylyl cyclase, degree of sequence similarity and their overlapping pharmacological specificities. The subfamily is comprised of five different receptors 5-HT1A, 5-HT1B, 5-HT1D, 5-HT1E, 5-HT1F, and they can couple to Gi/Go and mediate inhibitory neurotransmission, although signalling via other transduction systems are known. One of the 5-HT1 receptors, the 5-HT1E receptor, is yet to achieve receptor status from the International Union of Basic and Clinical Pharmacology (IUPHAR), since a robust response mediated via the protein has not been reported in the literature.
The 5-HT1B receptor is almost pharmacologically identical to the 5-HT1D receptor, but has a much higher expression level [PMID: 9559931, PMID: 9453271]. 5-HT1B receptors are expressed in the CNS. They induce presynaptic inhibition [PMID: 1578282, PMID: 10234032, PMID: 11080193] and influence behaviour [PMID: 8091214, PMID: 15380839]. They also have vascular effects, such as pulmonary vasoconstriction [PMID: 20945968]. The receptors are therapeutic targets of the antimigraine 'triptans' (e.g. sumitriptan and zolmitriptan), which are non-selective 5-HT1D/1B receptor agonists [PMID: 10193663]. In addition to the antimigraine activity of such drugs, other therapeutic uses include effects on bipolar disorder, autism and as anti-aggression agents [PMID: 12052194, PMID: 8091214, PMID: 20945968]. 5-HT1B receptors may also have a role in the regulation of bone, since blocking 5-HT1B receptors decreases the number of osteoblasts, bone mass, and the bone formation rate [PMID: 19041748].
GO:0004993 G-protein coupled serotonin receptor activity
GO:0005887 integral component of plasma membrane