Adenosine Triphosphate : an Inhibitor of Generation of Thromboplastin

Abstract

IN a series of experiments designed to investigate the possible existence of a relationship between energy metabolism and blood clotting mechanisms, the inactivation of human thromboplastin by adenosine triphosphate (ATP) has been noted (Table 1). The thromboplastin system is assayed for activity by determining the clotting time after adding 0.1 ml. of the reaction mixture, described in Table 1, to 0.1 ml. of 1 : 10 citrated (0.1 M trisodium citrate) substrate plasma. The substrate plasma had been recalcified exactly 15 sec earlier with 0.1 ml. calcium chloride. At maximum generation of thromboplastic activity, 0.08 ml. of ATP (0.1 M) or saline is added to the test system. This approach allows removal of 0.1 ml. of the reaction mixture for a clotting time assay before addition of ATP or saline. Concentration of ATP in the reaction mixture following removal of the 0.1 ml. aliquot is 0.0087 M.