Summary
Since ticlopidine specifically inhibits ADP-induced platelet aggregation without affecting
prostaglandin metabolism, it seemed interesting to evaluate the effect of aspirin
with regard to the antithrombotic efficacy of ticlopidine. Ticlopidine was administered
orally to rats alone or in combination with aspirin and the efficacy of the association
was determined in several experimental models. A synergistic effect of the ticlopidine/aspirin
association was demonstrated with regard to ADP- and collagen-induced platelet aggregation
measured ex vivo but also in several experimental thrombosis models including silk
thread-induced thrombosis in an arteriovenous shunt, wire coil-induced thrombosis
and 111In-labelled platelet deposition on the subendothelium following air drying injury
of the rat carotid artery. Similar results were obtained with regard to myointimal
proliferation following air-induced injury of the rat carotid artery which occurred
as a consequence of vascular injury. The ticlopidine/aspirin combination showed only
additive-type effects on bleeding time prolongation induced by tail transection in
the rat.
