Histamine H3 Receptors

Histamine H3 receptors are Gαi/o-protein-coupled receptors expressed at high levels on histaminergic neurons in the CNS, particularly in the basal ganglia, cortex and hippocampus. H3 receptors are thought to function as presynaptic autoreceptors.

Literature (2)
Gene Data

Histamine H3 Receptor Agonists

Cat. No. Product Name / Activity
3545 Histamine dihydrochloride
Endogenous histamine receptor agonist
0729 Imetit dihydrobromide
Standard H3 and H4 agonist (H3 > H4)
0932 Immepip dihydrobromide
Standard H3 agonist. Also H4 agonist
2315 Immethridine dihydrobromide
Potent H3 agonist, highly selective over H4
0569 (R)-(-)-α-Methylhistamine dihydrobromide
Potent, standard H3 agonist

Histamine H3 Receptor Inverse Agonists

Cat. No. Product Name / Activity
3743 BF 2649 hydrochloride
Potent and selective H3 inverse agonist

Histamine H3 Receptor Antagonists

Cat. No. Product Name / Activity
0752 Clobenpropit dihydrobromide
Highly potent H3 antagonist and H4 partial agonist
0779 Iodophenpropit dihydrobromide
Potent, selective H3 antagonist
4020 JNJ 5207852 dihydrochloride
High affinity H3 antagonist
0644 Thioperamide
H3 antagonist; also H4 inverse agonist

Histamine H3 receptors are Gαi/o-protein-coupled receptors first cloned in 1999. H3 receptors are expressed at high levels on histaminergic neurons in the central nervous system, particularly in the basal ganglia, cortex, hippocampus and strial area. They are expressed in the periphery at lower densities in the gastrointestinal, bronchial and cardiovascular systems.

H3 receptors are thought to function as presynaptic autoreceptors and their activation stimulates the negative feedback mechanism that reduces central histaminergic activity. These receptors have displayed heterogeneity in binding and functional studies, suggesting multiple subtypes. In rats, three H3 receptor subtypes have been identified and they all vary in the length of the third extracellular loop, have distinct CNS localization and differentially couple to adenylyl cyclase and MAPK signaling pathways.

H3 receptors have multiple functions including roles in cognition, sleep-wake status, energy homeostasis regulation and inflammation. Activation of these receptors can inhibit histamine, dopamine, serotonin, noradrenalin and acetylcholine release and they participate in control of neurogenic inflammation through local-neuron feedback loops. Furthermore, H3 receptor activation increases antigen-presenting cell capacity.

H3 receptors are thought to have pathophysiological relevance and are involved in cognitive impairment, seizures and possibly metabolic syndrome. The human gene encoding this receptor is localized to chromosome 20q13.33.

External sources of pharmacological information for Histamine H3 Receptors :

Literature for Histamine H3 Receptors

Tocris offers the following scientific literature for Histamine H3 Receptors to showcase our products. We invite you to request* your copy today!

*Please note that Tocris will only send literature to established scientific business / institute addresses.

Histamine Receptors Scientific Review

Histamine Receptors Scientific Review

Written by Iwan de Esch and Rob Leurs, this review provides a synopsis of the different histamine receptor subtypes and the ligands that act upon them; compounds available from Tocris are listed.

Alzheimer's Disease Poster

Alzheimer's Disease Poster

Alzheimer's disease (AD) is a debilitating and progressive neurodegenerative disease and the most common cause of dementia, affecting approximately 30% of individuals aged over 85 years. This poster summarizes the cellular and molecular mechanisms of AD.

Histamine H3 Receptor Gene Data

Species Gene Symbol Gene Accession No. Protein Accession No.
Human HRH3 NM_007232 Q9Y5N1
Mouse Hrh3 NM_133849 P58406
Rat Hrh3 NM_053506 Q9QYN8