Biomaterial Database

Differential involvement of membrane (Na-K)ATPase in thrombin- and trypsin-mediated platelet activation. 1992

P Finotti

Department of Pharmacology, University of Padova, Italy.

The possibility that platelet activation may also involve membrane (Na-K)ATPase was investigated by testing the effects of both proteinases on platelet shape change and aggregation in the absence and presence of the specific (Na-K)ATPase inhibitor ouabain. Ouabain (8 to 80 microM) completely antagonized trypsin-induced platelet shape change and aggregation when it was preincubated with platelet suspension before the addition of trypsin. Unlike trypsin, thrombin-induced platelet activation was significantly enhanced by ouabain. It was also observed that on partially purified beef heart (Na-K)ATPase preparation, thrombin significantly enhanced the enzyme inhibition caused by submaximal inhibitory concentrations of ouabain. Soybean trypsin inhibitor (4 micrograms/ml) employed as the agent capable to counteract proteinase effects on the (Na-K)ATPase, was shown both to prevent and antagonize the platelet activation induced by trypsin (0.3 to 1.5 micrograms/ml), but it failed to modify the responses evoked by thrombin. It is concluded that membrane (Na-K)ATPase is involved differently in platelet activation by trypsin and thrombin probably because receptor sites to which either proteinase on the platelet surface binds, are distinct. Direct enzyme involvement is indeed apparent only in trypsin-induced platelet activation.

UI	MeSH Term	Description	Entries
D010042	Ouabain	A cardioactive glycoside consisting of rhamnose and ouabagenin, obtained from the seeds of Strophanthus gratus and other plants of the Apocynaceae; used like DIGITALIS. It is commonly used in cell biological studies as an inhibitor of the NA(+)-K(+)-EXCHANGING ATPASE.	Acocantherin,G-Strophanthin,Acolongifloroside K,G Strophanthin
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
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
D002462	Cell Membrane	The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.	Plasma Membrane,Cytoplasmic Membrane,Cell Membranes,Cytoplasmic Membranes,Membrane, Cell,Membrane, Cytoplasmic,Membrane, Plasma,Membranes, Cell,Membranes, Cytoplasmic,Membranes, Plasma,Plasma Membranes
D004305	Dose-Response Relationship, Drug	The relationship between the dose of an administered drug and the response of the organism to the drug.	Dose Response Relationship, Drug,Dose-Response Relationships, Drug,Drug Dose-Response Relationship,Drug Dose-Response Relationships,Relationship, Drug Dose-Response,Relationships, Drug Dose-Response
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000254	Sodium-Potassium-Exchanging ATPase	An enzyme that catalyzes the active transport system of sodium and potassium ions across the cell wall. Sodium and potassium ions are closely coupled with membrane ATPase which undergoes phosphorylation and dephosphorylation, thereby providing energy for transport of these ions against concentration gradients.	ATPase, Sodium, Potassium,Adenosinetriphosphatase, Sodium, Potassium,Na(+)-K(+)-Exchanging ATPase,Na(+)-K(+)-Transporting ATPase,Potassium Pump,Sodium Pump,Sodium, Potassium ATPase,Sodium, Potassium Adenosinetriphosphatase,Sodium-Potassium Pump,Adenosine Triphosphatase, Sodium, Potassium,Na(+) K(+)-Transporting ATPase,Sodium, Potassium Adenosine Triphosphatase,ATPase Sodium, Potassium,ATPase, Sodium-Potassium-Exchanging,Adenosinetriphosphatase Sodium, Potassium,Pump, Potassium,Pump, Sodium,Pump, Sodium-Potassium,Sodium Potassium Exchanging ATPase,Sodium Potassium Pump
D001665	Binding Sites	The parts of a macromolecule that directly participate in its specific combination with another molecule.	Combining Site,Binding Site,Combining Sites,Site, Binding,Site, Combining,Sites, Binding,Sites, Combining
D013917	Thrombin	An enzyme formed from PROTHROMBIN that converts FIBRINOGEN to FIBRIN.	Thrombase,Thrombin JMI,Thrombin-JMI,Thrombinar,Thrombostat,alpha-Thrombin,beta,gamma-Thrombin,beta-Thrombin,gamma-Thrombin,JMI, Thrombin