[Activation of the anticlotting system by perfusion of the carotid sinus with prethrombin 1 in rabbits].

I.v. administration of prethrombin-1 activates the anticoagulating system but not through the thrombin generation. Perfusion of the rabbit humorally isolated carotid sinus with the prethrombin-1 increases the time of plasma recalcification, total fibrinolytic activity and nonenzymatic fibrinolysis, the effect depending on the prethrombin-1 concentration. The data obtained suggest that the prethrombin-1 is able to activate function of the anticoagulating system interacting with chemoreceptors of the isolated carotid sinus. The prethrombin-1 as well as alpha-thrombin induce similar effects in the anticoagulating system. Therefore the activation of the anticoagulating system is due to areas of chemoreceptors binding in the system and not to presence of the enzyme active center.