Influence of anti-platelet drugs on platelet-vessel waif interacticnks

The influence of in vitro treatment of platelets with antiplatelet drugs on the interaction of these cells with the subendothelium was studied using citrated human blood obtained from normal control donors. Reconstituted blood following drug treatment was circulated thwaigh a special chamber which housed averted segments of de-ardothelialized rabbit aorta. The wall shear rate used in these studies was 800 sec^−l. Surface coverage of platelets on the subsndothelium were morptrically evaluated. Aspirin, Ibuprofen, Prostaglandin E_l and 13 Azaprostanoic acid significantly reduced platelet thrombi an exposed sabendothelium. The calcium antagonists, Quin 2 and Diltiazem, exerted similar inhibitory effects, whereas Verapamil was a poor inhibitor. Aspirin treatment significantly enhanced platelet adhesion to the exposed vascular surface. Salicylate and Salicylamide did not enhance platelet. Only Aspirin enhanced the formation of lipcaygonase metabolites of radiolabeled arachidonate.Results suggest that drugs which inhibit platelet aggregation and seerertion of granule cot*Ants reduce formation of platelet thrombi. However, these drugs may or may not have a similar influence on platelet interaction with the subendathelium leading to spreading, adherence or formation of aggregates.