Inhibition of adrenaline-potentiated thrombin-induced reaction of human blood platelets by dihydroergotoxine.

The potentiating effect of adrenaline on thrombin-induced aggregation and release reaction of human blood platelets has been studied in vitro. Both reactions are inhibited by low doses of dihydroergotoxine. The inhibition of aggregation is of competitive type. The adrenaline-potentiated thrombin-induced platelet aggregation is inhibited also after intravenous injection of dihydroergotoxine. The pathophysiological implications of these findings are discussed.