Effects of arachidonic acid on the metabolism of eicosapentaenoic acid in washed human platelets.
We examined effects of arachidonic acid (AA) on eicosapentaenoic acid (EPA) metabolism in washed human platelets. Although human platelets had been considered to metabolize scarcely EPA, a simultaneous addition of EPA and AA to washed platelet suspensions stimulated markedly EPA metabolism. In addition, the stimulatory effect was more potent over the formation of thromboxane (TX) B3 than that of 12-hydroxy-5,8,10,14,17-eicosapentaenoic acid (HEPE). The stimulation by AA can be due to AA itself and/or AA metabolites. Indomethacin decreased the stimulatory effect of AA on the HEPE formation, suggesting that cyclooxygenase product(s) of AA stimulated the HEPE formation. Among the metabolites of AA investigated, prostaglandin (PG)G2 and 12-hydroperoxy-5,8,10,14-eicosatetraenoic acid had the stimulatory effect on both TXB2 and HEPE formations, whereas PGH2, PGD2, TXB2 and 12-hydroxy-5, 8,10,14-eicosatetraenoic acid were ineffective.
D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000097:blood / Q000494:pharmacology*; D001241:Aspirin / Q000494:pharmacology; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism*; D002250:Carbon Radioisotopes; D015118:Eicosapentaenoic Acid / Q000097:blood*; D006801:Humans; D006893:Hydroxyeicosatetraenoic Acids / Q000494:pharmacology; D007213:Indomethacin / Q000494:pharmacology; D007700:Kinetics; D011462:Prostaglandins G / Q000494:pharmacology
D001095:Arachidonic Acids; D002250:Carbon Radioisotopes; D006893:Hydroxyeicosatetraenoic Acids; D011462:Prostaglandins G; D016718:Arachidonic Acid; C038291:prostaglandin G2; D015118:Eicosapentaenoic Acid; D001241:Aspirin; D007213:Indomethacin