The effects of aspirin and dipyridamole on the metabolism of arachidonic acid in human platelets.
The effects of aspirin and dipyridamole on the metabolism of exogenous 14C-arachidonic acid were investigated in intact human platelets in vitro. The formation of thromboxane B2 (TXB2) and 12-hydroxy-5,8,10-heptadecatrienoic acid (HHT) was inhibited dose dependently by aspirin but not by dipyridamole. Neither was the aspirin caused inhibition in TXB2 and HHT formation modified by dipyridamole. At high concentrations aspirin caused a slight increase in the amount of 12-hydroperoxy-5,8,10,14-eicosatetraenoic acid (12-HPETE) and a corresponding decrease in that of 12-hydroxy-5,8,10,14-eicosatetraenoic acid (12-HETE). This was seen also when aspirin was combined with dipyridamole. At high concentrations (100 microM and 1 mM) dipyridamole caused an increased formation of 12-HETE and an unidentified metabolite group. The present study indicates that dipyridamole has no effect on the formation of the cyclo-oxygenase metabolites in human platelets but the lipoxygenase pathway seems to be stimulated by dipyridamole.
D019377:12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; D000328:Adult; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000378:metabolism*; D001241:Aspirin / Q000494:pharmacology*; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism*; D004176:Dipyridamole / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005231:Fatty Acids, Unsaturated / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D015289:Leukotrienes; D008297:Male; D013929:Thromboxane B2 / Q000378:metabolism
D001095:Arachidonic Acids; D005231:Fatty Acids, Unsaturated; D015289:Leukotrienes; D016718:Arachidonic Acid; D013929:Thromboxane B2; D019377:12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; D004176:Dipyridamole; C021201:12-HPETE; C026222:12-hydroxy-5,8,10,14-heptadectetraenoic acid; D001241:Aspirin