Platelet prostanoids in interaction of platelets with collagen substrates. II. Effects of exogenous arachidonic acid, stable PG endoperoxides analogue, and aspirin.
The effects of (i) the exogenous arachidonic acid (AA), (ii) stable PG endoperoxide analogue U46619, and (iii) cyclooxygenase inhibitor aspirin on the interaction of platelets with a surface coated with commercial fibrillar calf skin collagen (CSC) were studied using scanning electron microscopy. AA and U46619 stimulate massive spreading of platelets on the CSC substrate and formation of the surface-bound multilayer (thrombi-like) aggregates. The stimulation of spreading and formation of thrombi-like aggregates induced by AA correlate with the TXA2 synthesis in platelets. Unlike AA, U46619 induces these processes without transformation into TXA2 and stimulation of its synthesis in platelets. Aspirin prevents the AA-induced platelet spreading, formation of the surface-bound thrombi-like aggregates, and TXA2 synthesis. In the absence of soluble platelet inducers, aspirin decreases the CSC substrate-induced disc - sphere transformation and spreading of platelets, but doesn't affect the initial attachment of platelets to the CSC substrate.
D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; D000818:Animals; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000494:pharmacology*; D001241:Aspirin / Q000494:pharmacology*; D001792:Blood Platelets / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure; D002417:Cattle; D003094:Collagen / Q000494:pharmacology*; D006801:Humans; D010974:Platelet Aggregation / Q000187:drug effects*; D011450:Prostaglandin Endoperoxides, Synthetic / Q000494:pharmacology*; D013917:Thrombin / Q000502:physiology; D013931:Thromboxanes / Q000097:blood
D001095:Arachidonic Acids; D011450:Prostaglandin Endoperoxides, Synthetic; D013931:Thromboxanes; D016718:Arachidonic Acid; D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; D003094:Collagen; D013917:Thrombin; D001241:Aspirin