Biomaterial Database

Selective displacement of [3H]mepyramine from peripheral vs. central nervous system receptors by loratadine, a non-sedating antihistamine. 1986

H S Ahn, and A Barnett

Displacement of [3H]mepyramine binding was compared in membranes from guinea-pig lung vs. cerebral cortex as a measure of affinity for peripheral vs. central nervous system (CNS) histamine receptors. Loratadine, a new non-sedating antihistamine, was found to be the only compound tested which was selective for lung (Ki = 35 nM) vs. cortex (Ki = 118 nM). This difference is statistically significant (P less than 0.05) whereas there was no significant (P greater than 0.05) difference in the Kis between the 2 tissues for terfenadine, astemizole, mequitazine or chlorpheniramine. It is concluded from these and other studies that the lack of significant sedative effects shown with loratadine is due to its poor penetration into the CNS and selectivity for peripheral histamine receptors.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008168	Lung	Either of the pair of organs occupying the cavity of the thorax that effect the aeration of the blood.	Lungs
D008297	Male		Males
D010880	Piperidines	A family of hexahydropyridines.
D011738	Pyrilamine	A histamine H1 antagonist. It has mild hypnotic properties and some local anesthetic action and is used for allergies (including skin eruptions) both parenterally and locally. It is a common ingredient of cold remedies.	Mepyramine,Pyranisamine,Anthisan,Boots Bite & Sting Relief,Kriptin,Mepyramine Maleate,Pyrilamine Maleate,Maleate, Mepyramine,Maleate, Pyrilamine
D011956	Receptors, Cell Surface	Cell surface proteins that bind signalling molecules external to the cell with high affinity and convert this extracellular event into one or more intracellular signals that alter the behavior of the target cell (From Alberts, Molecular Biology of the Cell, 2nd ed, pp693-5). Cell surface receptors, unlike enzymes, do not chemically alter their ligands.	Cell Surface Receptor,Cell Surface Receptors,Hormone Receptors, Cell Surface,Receptors, Endogenous Substances,Cell Surface Hormone Receptors,Endogenous Substances Receptors,Receptor, Cell Surface,Surface Receptor, Cell
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
D006168	Guinea Pigs	A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research.	Cavia,Cavia porcellus,Guinea Pig,Pig, Guinea,Pigs, Guinea
D006634	Histamine H1 Antagonists	Drugs that selectively bind to but do not activate histamine H1 receptors, thereby blocking the actions of endogenous histamine. Included here are the classical antihistaminics that antagonize or prevent the action of histamine mainly in immediate hypersensitivity. They act in the bronchi, capillaries, and some other smooth muscles, and are used to prevent or allay motion sickness, seasonal rhinitis, and allergic dermatitis and to induce somnolence. The effects of blocking central nervous system H1 receptors are not as well understood.	Antihistamines, Classical,Antihistaminics, Classical,Antihistaminics, H1,Histamine H1 Antagonist,Histamine H1 Receptor Antagonist,Histamine H1 Receptor Antagonists,Histamine H1 Receptor Blockaders,Antagonists, Histamine H1,Antagonists, Histamine H1 Receptor,Antihistamines, Sedating,Blockaders, Histamine H1 Receptor,First Generation H1 Antagonists,H1 Receptor Blockaders,Histamine H1 Blockers,Receptor Blockaders, H1,Antagonist, Histamine H1,Classical Antihistamines,Classical Antihistaminics,H1 Antagonist, Histamine,H1 Antagonists, Histamine,H1 Antihistaminics,Sedating Antihistamines
D000631	Aminopyridines	Pyridines substituted in any position with an amino group. May be hydrogenated but must retain at least one double bond.	Aminopyridine