Effect of 1-O-alkyl-2-acetyl-sn-glyceryl-3-phosphorylcholine on calcium fluxes by human platelet microsomes.
Under conditions where optimal concentrations of arachidonic acid, phosphatidic acid, or the calcium ionophore A23187 caused release of 50-95% of calcium from preloaded platelet microsomes, basophil platelet activating factor (1-O-alkyl-2-acetyl-sn-glyceryl-3-phosphorylcholine, AGEPC) did not cause the release of calcium at concentrations as high as 2 X 10(-5) M. The failure to stimulate calcium release was not due to metabolism or inactivation of AGEPC. These results show that AGEPC is not a calcium ionophore and is unable to directly effect the release of calcium from microsomes by mechanisms other than ionophoric action. The increase in intracellular levels that occurs during AGEPC-induced platelet aggregation must be an indirect effect of the AGEPC.
D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000494:pharmacology; D001692:Biological Transport / Q000187:drug effects; D001792:Blood Platelets / Q000648:ultrastructure*; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D006801:Humans; D008861:Microsomes / Q000378:metabolism*; D010712:Phosphatidic Acids / Q000494:pharmacology; D010972:Platelet Activating Factor / Q000494:pharmacology*
D001095:Arachidonic Acids; D010712:Phosphatidic Acids; D010972:Platelet Activating Factor; D016718:Arachidonic Acid; D000001:Calcimycin; D002118:Calcium