Antiaccelerator (Anticonvertin) Activity of Canine Plasma and Serum.

Abstract

Activity of serum accelerator preparations (SA) rich in convertin is rapidly lost on incubation with canine plasma. It is shown that antiaccelerator activity is present in approximately equal amounts in normal and hemophilic canine plasma and in normal serum. An assay of antiaccelerator activity is described. Antiaccelerator activity is retained after dialysis, but is thermol-abile and is inactivated by ether extractions. It is found in the precipitate obtained between 50 and 80% saturation with ammonium sulfate. Separation from antithrombin was not accomplished. It is suggested that the new activity limits the tide of SA during clotting, analogous to antithrombin and the thrombin tide.