Biomaterial Database

Subclasses of histamine H3 antagonist binding sites in rat brain. 1994

P Cumming, and A Gjedde

Montreal Neurological Institute, Qué, Canada.

Histamine H3 antagonists have been reported to discriminate subclasses of histamine H3 agonist binding in rat cortical membranes. This phenomenon was investigated by autoradiography of cryostat sections of rat forebrain labelled with [3H]N alpha-methylhistamine ([3H]NAMH, 4 nM). Displacement curves with thioperamide detected a single site in cortex and striatum (pIC50 = 8.18 +/- 0.03). However, Hill coefficients (nH = 0.51 +/- 0.12) suggested the possible presence of multiple binding sites. Displacement with burimamide was consistent with two site models in all brain regions examined (pIC50(A) = 7.9 +/- 1.5; pIC50(B) = 5.6 +/- 0.7), except for the medial septum where a single site was detected. Elsewhere, the relative abundance of the two sites displaced by burimamide (H3A:H3B) appeared to be 1:2. Thioperamide may have failed to discriminate two sites because the IC50s were too similar to be distinguished in the present autoradiographic study.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D008761	Methylhistamines	Histamine substituted in any position with one or more methyl groups. Many of these are agonists for the H1, H2, or both histamine receptors.
D009928	Organ Specificity	Characteristic restricted to a particular organ of the body, such as a cell type, metabolic response or expression of a particular protein or antigen.	Tissue Specificity,Organ Specificities,Specificities, Organ,Specificities, Tissue,Specificity, Organ,Specificity, Tissue,Tissue Specificities
D010880	Piperidines	A family of hexahydropyridines.
D001921	Brain	The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.	Encephalon
D002049	Burimamide	An antagonist of histamine that appears to block both H2 and H3 histamine receptors. It has been used in the treatment of ulcers.
D002540	Cerebral Cortex	The thin layer of GRAY MATTER on the surface of the CEREBRAL HEMISPHERES that develops from the TELENCEPHALON and folds into gyri and sulci. It reaches its highest development in humans and is responsible for intellectual faculties and higher mental functions.	Allocortex,Archipallium,Cortex Cerebri,Cortical Plate,Paleocortex,Periallocortex,Allocortices,Archipalliums,Cerebral Cortices,Cortex Cerebrus,Cortex, Cerebral,Cortical Plates,Paleocortices,Periallocortices,Plate, Cortical
D003342	Corpus Striatum	Striped GRAY MATTER and WHITE MATTER consisting of the NEOSTRIATUM and paleostriatum (GLOBUS PALLIDUS). It is located in front of and lateral to the THALAMUS in each cerebral hemisphere. The gray substance is made up of the CAUDATE NUCLEUS and the lentiform nucleus (the latter consisting of the GLOBUS PALLIDUS and PUTAMEN). The WHITE MATTER is the INTERNAL CAPSULE.	Lenticular Nucleus,Lentiform Nucleus,Lentiform Nuclei,Nucleus Lentiformis,Lentiformis, Nucleus,Nuclei, Lentiform,Nucleus, Lenticular,Nucleus, Lentiform,Striatum, Corpus
D006633	Histamine Antagonists	Drugs that bind to but do not activate histamine receptors, thereby blocking the actions of histamine or histamine agonists. Classical antihistaminics block the histamine H1 receptors only.	Antihistamine,Antihistamines,Histamine Antagonist,Antagonist, Histamine,Antagonists, Histamine
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia