Inhibition of whole blood prothrombin time by lactadherin or annexin V.

Fresh whole blood was anticoagulated with 10 mM citrate and 25 μg/mL corn trypsin inhibitor. After addition of indicated quantities of lactadherin (▴) or annexin V (●), the blood was diluted 1:1 with 50 pM tissue factor and 10 mM Ca⁺⁺. Time to fibrin-strand formation was measured with a fibrometer. Results are displayed as the ratio of prothrombin time for blood treated with annexin V or lactadherin to prothrombin time for control blood from the same donor, with the same elapsed time since phlebotomy. Results displayed are mean ± SD for triplicate samples from a single experiment representative of 3 experiments.