Influence of aspirin, molsidomine, trapidil, and some trapidil derivatives on arachidonic acid induced reversible thrombocyte aggregation in the rabbit.

For testing antiaggregatory activity of substances in vivo we used transient decrease of circulating platelet number in rabbit blood after rapid i. v. injection of arachidonic acid (AA) as sign of increased thrombocyte aggregates within the tissues. We tested aspirin, molsidomine, trapidil, and 6 trapidil derivatives. Antiaggregatory effects of aspirin, molsidomine, and trapidil confirm former reports and reliability of the used model. 4 trapidil derivatives were effective in doses lower than trapidil itself.