title: Superoxide dismutase triggers activation of "primed" platelets.
abstract: Superoxide dismutase (SOD) triggers activation of human platelets exposed to subthreshold concentrations of arachidonic acid and collagen. The subthreshold concentrations used are not able to activate platelets but "prime" platelets to be activated by SOD. The addition of SOD to arachidonic acid-or collagen-primed platelets induced aggregation, thromboxane A2 production, and release of [3H]serotonin. Superoxide dismutase does not have any effect on resting platelets and ADP-, thrombin-, calcium ionophore A23187-, PAF-, or U46619-stimulated platelets. Furthermore, superoxide dismutase-dependent platelet activation is fully prevented by catalase and/or aspirin, suggesting a role for H2O2 and the involvement of the cyclooxygenase pathway of arachidonic acid in such activation.
authors.affiliation: Institute of 1st Clinical Medicine, University of Rome, La Sapienza, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Iuliano
authors.forename: D
authors.initials: D
authors.lastname: Praticò
authors.forename: A
authors.initials: A
authors.lastname: Ghiselli
authors.forename: M S
authors.initials: MS
authors.lastname: Bonavita
authors.forename: F
authors.initials: F
authors.lastname: Violi
mesh_terms: D000328:Adult; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000494:pharmacology; D001241:Aspirin / Q000494:pharmacology; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism; D002374:Catalase / Q000494:pharmacology; D003094:Collagen / Q000494:pharmacology; D006801:Humans; D008297:Male; D015539:Platelet Activation / Q000187:drug effects*; D010974:Platelet Aggregation / Q000187:drug effects; D012701:Serotonin / Q000097:blood; D013482:Superoxide Dismutase / Q000494:pharmacology*; D013928:Thromboxane A2 / Q000097:blood
chemical_list: D001095:Arachidonic Acids; D016718:Arachidonic Acid; D012701:Serotonin; D013928:Thromboxane A2; D003094:Collagen; D002374:Catalase; D013482:Superoxide Dismutase; D001241:Aspirin