Ticlopidine inhibits platelet thrombus formation studied in a flowing system

We have studied the effect of ticlopidine on platelet function. This effect was assessed by aggregation studies and by the Baumgartner perfusion system as an ex vivo approach to study modifications in the interaction of platelets with vascular subendothelium. Platelets from volunteers, that were given 250 mg of ticlopidine twice a day showed a significantly decreased aggregation of platelets induced by several agonists. In the perfusion studies a marked reduction in the parameters that measure platelet interaction with subendothelium was also observed. The decrease in thrombus formation, and the diminished size of platelet aggregates, clearly indicated that ticlopidine impaired platelet-platelet interaction in this experimental flowing system. Our results suggest that ticlopidine is a potent inhibitor of platelet function and that its antiplatelet activity might be related to the mechanisms that regulate the interaction between platelets at the membrane level.