Three different heparin-catalyzed inhibitor/protease reactions were studied: antithrombin III/thrombin, heparin cofactor II/thrombin, antithrombin III/factor Xa. The three reactions were saturable with respect to both inhibitor and protease. The initial reaction velocity, for each reaction, could be described by the general rate equation for a random-order bireactant enzyme-catalyzed reaction. ...

The functional levels of antithrombin III, plasminogen, plasmin, and alpha-2-antiplasmin were evaluated in sequentially derived fresh frozen plasma, cryoprecipitate, and cryo-poor plasma aliquots from 20 registered blood donors. Antithrombin III is the major plasma inhibitor of the serine proteases of the procoagulant system. Plasminogen, the proenzymatic form of plasmin, is the primary endogen...

Inactivation of plasmin by a 3-4-fold molar excess of antithrombin III follows pseudo-first-order kinetics and the apparent rate constants are proportional to the concentration of the inhibitor. Heparin accelerates the inactivation reaction without changing its pseudo-first-order character, and the apparent rate constants are also proportional to the concentration of the polysaccharide. Heparin...

BACKGROUND One of the rare causes of venous thromboembolism in pregnancy is antithrombin III deficiency. Antithrombin III deficiency is estimated to carry a 30% risk of venous thrombotic complication during each pregnancy and postpartum. CASE DETAILS We present thea case of a A 21-year-old pregnant woman (Para 1+) with a history of large atrial septal defect repair at our hospital (Imam Ali H...

In this prospective study, antithrombin III, plasminogen and alpha 2 antiplasmin which are synthetised by the liver were measured and compared with the Normotest, Thrombotest and fibrinogen concentrations in 92 consecutive jaundiced patients. Antithrombin III appeared to be the most discriminant coagulation test in differentiating hepatocellular from cholestatic jaundice. A high correlation was...

BACKGROUND Heparin needs the plasma protein antithrombin III to function as an inhibitor of thrombin, and local antithrombin III deficiency might therefore limit the antithrombotic effectiveness of heparin during percutaneous transluminal coronary angioplasty. METHODS AND RESULTS In the present double-blind study, 615 consecutive patients undergoing percutaneous transluminal coronary angiopla...