[Stimulation of the secondary anticlotting system by DFP-alpha-thrombin]

Inhibition of the alpha--thrombin DFP catalytic portion does not incapacitate it physiologically: i. v. administration of such thrombin stimulates the second anticoagulating system. Aminasin abolishes this effect. These findings suggest that the thrombin preserves the portion of molecule responsible for reflex stimulation of the anticoagulating system. Microstructural changes of the apolar portion in different conditions deprives the alpha--thrombin to its ability to interact with the vascular bed's chemoreceptors. I. v. administration of such thrombin evoked no defense response in the organism.