Kinetic Aspects of the Interaction of Blood-Clotting Enzymes

Abstract

It is demonstrated that clotting time in a thrombotest experiment bears a linear relationship to the inverse of factor X concentration under conditions in which the ratio of factor X to the factors II and VII is equal to or smaller than the ratio in normal plasma. A similar relationship occurs with other thromboplastins as long as factor V and fibrinogen are present in excess, i. e. when the dilutions are made with BaSO₄ absorbed plasma. Contact activation causes deviation from the observed straight-line relationship. ^* Present address : State Univ. of New York at Buffalo, Med. Sch., N. Y., U. S. A. ^** Present address : Rivadavia Hospital, Buenos Aires, Argentina.