Study of platelet aggregation in vivo i. Effect of bencyclan.

A 20mu diameter pore size screen was inserted into an arterio-venous bypass system in heparinized stumptailed monkeys. ADP and serotonin injection resulted in aggregation of platelets on the screen and consecutive increase in pre-screen pressure and decrease in post-screen pressure. From these changes an "aggregation index" was calculated. Bencyclan in doses of 0.5-15 mg/kg inhibited platelet aggregation in vivo. Doses of 20 mg/kg or above showed some hemolytic effect, no other undesirable effects were seen.