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DOI: 10.1055/s-0038-1650243
The Antithrombotic Effect of Aurin Tricarboxylic Acid in the Guinea Pig Is not Solely due to Its Interaction with the von Willebrand Factor-GPIb Axis
Publikationsverlauf
Received: 18. Januar 1995
Accepted after resubmission19. September 1995
Publikationsdatum:
10. Juli 2018 (online)


Summary
Commercial aurin tricarboxylic acid (ATA) has been reported to interfere specifically with von Willebrand factor-glycoprotein lb (vWF-GPIb) axis. This study was designed to explore the antithrombotic effects of AT A by examining its effects on guinea pig platelet function in vitro, in vivo and ex vivo. In vitro, addition of various concentrations of ATA to platelet-rich guinea pig plasma totally inhibited ristocetin-induced platelet aggregation, as expected. Unexpectedly, however, ATA similarly inhibited the aggregation induced by ADP, PAF, collagen, I-BOP (a thromboxane A2/prostaglandin H2 analogue) and arachidonic acid.
In vivo, the antithrombotic action of ATA was assessed in a model of acute platelet-dependent guinea pig mesenteric artery thrombosis triggered by laser-induced intimal injury. As the thrombotic response of arteries to such injury is a spontaneous cyclic recurrent process, 5 arteries in each animal were consecutively studied for 15 min each after i.v. bolus injection of 5, 7.5 or 10 mg/kg of ATA, which reduced the number of recurrent thrombi per artery in a dose-dependent manner. The highest dose of 10 mg/kg induced maximal inhibition of thrombus formation (72%, p <0.001) 5 min after injection.
Ex vivo, platelet aggregation was assessed in blood samples taken before and after i.v. bolus injection of 10 or 15 mg/kg ATA. Ten mg/kg significantly inhibited collagen-induced aggregation, and 15 mg/kg, the aggregation induced by ristocetin, ADP, PAF, collagen, I-BOP and arachidonic acid.
The results of the in vivo studies confirmed that ATA is an effective antithrombotic agent. In the in vitro and ex vivo studies, ristocetin-induced platelet aggregation confirmed that ATA interacts with the vWF-GPIb axis, and suggests that the final common pathway of the aggregation induced by other agents tested consists of fibrinogen binding to the platelet GPIIb/IIIa receptor. We conclude that ATA interferes with vWF binding to GPIb, that it may interact with fibrinogen binding to GPIIb/IIIa, and that it might possess potent antithrombotic properties in platelet-mediated thrombosis.