Biomaterial Database

Mepyramine inhibits platelet activating factor-induced rabbit platelet aggregation: role of intracellular histamine. 1997

S Zeng, and Z G Guo

Laboratory of Molecular Pharmacology, Hunan Medical University, Changsha, China.

OBJECTIVE To study the possible role of intracellular histamine (HA) in platelet activating factor (PAF)-induced platelet activation. METHODS Washed rabbit platelet suspension was used to test the inhibitory effect of mepyramine (Mep, an H1 receptor antagonist) on PAF-induced platelet aggregation. The thromboxane B2 (TXB2) generation was measured by radioimmunoassay and the intracellular calcium ([Ca2+]i) concentration was determined by the specific fluorescence indicator Fura-2. RESULTS Mep > 100 mumol.L-1 generated a concentration-dependent inhibition on PAF-induced aggregation, with an IC50 value of 162 (95% confidence limits: 114-232 mumol.L-1). Cimetidine, an H2 receptor antagonist, even up to 400 mumol.L-1 had no effect on it. Exogenous HA (10 mumol.L-1) and H1 receptor agonist, 2-thiazolylethylamine had no energetic effect. alpha-Fluoromethylhistidine, an inhibitor of histidine decarboxylase, did not inhibit platelet responses. However, in platelets permeabilized with saponin (8-10 mg.L-1), exogenous HA attenuated the inhibitory effect of Mep to about 50% at a concentration of 50 mumol.L-1. Preincubation of platelets with Mep (100 or 200 mumol.L-1) resulted in an inhibition on TXB2 generation and [Ca2+]i elevation induced by PAF. CONCLUSIONS Platelets activated by PAF is associated with an intracellular HA synthesis and release via a common pathway of TXB2 generation and the rise of [Ca2+]i.

UI	MeSH Term	Description	Entries
D010972	Platelet Activating Factor	A phospholipid derivative formed by PLATELETS; BASOPHILS; NEUTROPHILS; MONOCYTES; and MACROPHAGES. It is a potent platelet aggregating agent and inducer of systemic anaphylactic symptoms, including HYPOTENSION; THROMBOCYTOPENIA; NEUTROPENIA; and BRONCHOCONSTRICTION.	AGEPC,Acetyl Glyceryl Ether Phosphorylcholine,PAF-Acether,Phosphorylcholine, Acetyl Glyceryl Ether,1-Alkyl-2-acetyl-sn-glycerophosphocholine,Platelet Aggregating Factor,Platelet Aggregation Enhancing Factor,Platelet-Activating Substance,Thrombocyte Aggregating Activity,1 Alkyl 2 acetyl sn glycerophosphocholine,Aggregating Factor, Platelet,Factor, Platelet Activating,PAF Acether,Platelet Activating Substance
D010974	Platelet Aggregation	The attachment of PLATELETS to one another. This clumping together can be induced by a number of agents (e.g., THROMBIN; COLLAGEN) and is part of the mechanism leading to the formation of a THROMBUS.	Aggregation, Platelet
D010975	Platelet Aggregation Inhibitors	Drugs or agents which antagonize or impair any mechanism leading to blood platelet aggregation, whether during the phases of activation and shape change or following the dense-granule release reaction and stimulation of the prostaglandin-thromboxane system.	Antiaggregants, Platelet,Antiplatelet Agent,Antiplatelet Agents,Antiplatelet Drug,Blood Platelet Aggregation Inhibitor,Blood Platelet Antagonist,Blood Platelet Antiaggregant,PAR-1 Antagonists,Platelet Aggregation Inhibitor,Platelet Antagonist,Platelet Antagonists,Platelet Antiaggregant,Platelet Antiaggregants,Platelet Inhibitor,Protease-Activated Receptor-1 Antagonists,Antiplatelet Drugs,Blood Platelet Aggregation Inhibitors,Blood Platelet Antagonists,Blood Platelet Antiaggregants,Platelet Inhibitors,Agent, Antiplatelet,Aggregation Inhibitor, Platelet,Antagonist, Blood Platelet,Antagonist, Platelet,Antiaggregant, Blood Platelet,Antiaggregant, Platelet,Drug, Antiplatelet,Inhibitor, Platelet,Inhibitor, Platelet Aggregation,PAR 1 Antagonists,Platelet Antagonist, Blood,Platelet Antiaggregant, Blood,Protease Activated Receptor 1 Antagonists
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
D011817	Rabbits	A burrowing plant-eating mammal with hind limbs that are longer than its fore limbs. It belongs to the family Leporidae of the order Lagomorpha, and in contrast to hares, possesses 22 instead of 24 pairs of chromosomes.	Belgian Hare,New Zealand Rabbit,New Zealand Rabbits,New Zealand White Rabbit,Rabbit,Rabbit, Domestic,Chinchilla Rabbits,NZW Rabbits,New Zealand White Rabbits,Oryctolagus cuniculus,Chinchilla Rabbit,Domestic Rabbit,Domestic Rabbits,Hare, Belgian,NZW Rabbit,Rabbit, Chinchilla,Rabbit, NZW,Rabbit, New Zealand,Rabbits, Chinchilla,Rabbits, Domestic,Rabbits, NZW,Rabbits, New Zealand,Zealand Rabbit, New,Zealand Rabbits, New,cuniculus, Oryctolagus
D001792	Blood Platelets	Non-nucleated disk-shaped cells formed in the megakaryocyte and found in the blood of all mammals. They are mainly involved in blood coagulation.	Platelets,Thrombocytes,Blood Platelet,Platelet,Platelet, Blood,Platelets, Blood,Thrombocyte
D002118	Calcium	A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.	Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation
D006632	Histamine	An amine derived by enzymatic decarboxylation of HISTIDINE. It is a powerful stimulant of gastric secretion, a constrictor of bronchial smooth muscle, a vasodilator, and also a centrally acting neurotransmitter.	Ceplene,Histamine Dihydrochloride,Histamine Hydrochloride,Peremin
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
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