Effect of Dicumarol on Concentration of the Labile Factor.

Abstract

The labile factor of the prothrombin complex remains relatively constant in the blood. Dicumarol causes a marked decrease in the prothrombin activity of rabbit and dog blood but does not reduce the concn. of the labile factor. The labile factor was assayed by determining the reduction of the prothrombin time of stored human plasma by adding a fixed dilution of the plasma to be assayed (after deprothrombinization with tricalcium phosphate).