Platelet aggregation and the ouabain-insensitive ATPase. Ecto-ATPase, reflection of membrane integrity.
The ecto-ATPase activity of washed human platelets has been characterized by a higher-performance liquid chromatographic method. Mg++ was found to stimulate ecto-ATPase activity more strongly than Ca++. The combination of Mg++ and Ca++ at increasing concentrations caused diminishing activity levels. Elevated ecto-ATPase activity was also found in platelets incubated with prostaglandin E1 (PGE1) or potassium cyanide (KCN). It is proposed that the increase of ecto-ATPase activity is related to the extrusion or exposure of plasma membrane containing a ouabain-insensitive ATPase. The role of ecto-ATPase in platelet aggregation is discussed in light of these findings.
D000251:Adenosine Triphosphatases / Q000378:metabolism* / Q000502:physiology; D001792:Blood Platelets / Q000201:enzymology*; D002118:Calcium / Q000494:pharmacology; D002462:Cell Membrane / Q000201:enzymology*; D002463:Cell Membrane Permeability; D002853:Chromatography, Liquid; D003486:Cyanides / Q000494:pharmacology; D006801:Humans; D008274:Magnesium / Q000494:pharmacology; D010042:Ouabain; D010974:Platelet Aggregation; D011188:Potassium / Q000494:pharmacology; D011458:Prostaglandins E / Q000494:pharmacology; D013268:Stimulation, Chemical
D003486:Cyanides; D011458:Prostaglandins E; D010042:Ouabain; D000251:Adenosine Triphosphatases; D008274:Magnesium; D011188:Potassium; D002118:Calcium