[Arterioarterial shunt coated with collagen. A model of acute arterial thrombosis for testing antithrombotic agents in rats].

We developed a new thrombosis model in Wistar rats. It consists of a shunt of which the central part is coated with collagen, a thrombogenic protein, implanted between the two carotid arteries of the rat. The occlusion time of the shunt is measured by a thermic method. The composition of the thrombus is analyzed by double isotope labeling of platelets and fibrinogen. Four antithrombotic drugs were studied: two antiplatelet agents, aspirin and clopidogrel; two anticoagulants, heparin and recombinant hirudin. The results show that aspirin alone does not increase the occlusion time of the shunt. Clopidogrel, heparin and hirudin at doses of 50 mg/kg, 500 IU/kg and 5 mg/kg significantly increase the thrombosis time but the composition of the thrombus varies according to the nature of the drug: antiplatelet (clopidogrel) or anticoagulant (heparin, hirudin). This model enables a plurifactorial analysis of acute arterial thrombosis and should be of value to discriminate the effects of antithrombotic and thrombolytic agents.