antithrombin(redirected from antithrombin III (AT III))
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any naturally occurring or therapeutically administered substance that neutralizes the action of thrombin and thus limits or restricts blood coagulation.
antithrombin I fibrin, referring to the capacity of fibrin to adsorb thrombin and thus neutralize it.
antithrombin III a naturally occurring inhibitor of blood coagulation; it is an α2-globulin member of the serpin group, synthesized in the liver and found in the plasma and various extravascular sites. It inactivates thrombin as well as certain coagulation factors and kallikrein. Inherited deficiency of the protein, an autosomal dominant disorder, is associated with recurrent deep vein thrombosis and pulmonary emboli. Complications from the disorder are prevented and, in conjunction with heparin, treated with a preparation of antithrombin III from pooled human plasma, administered intravenously.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.
Any substance that inhibits or prevents the effects of thrombin in such a manner that blood does not coagulate. A deficiency of antithrombin results in impaired inhibition of coagulation factors IIa, IXa, and Xa in plasma, causing recurrent thrombosis.
Farlex Partner Medical Dictionary © Farlex 2012
antithrombinA plasma protein that diminishes the activity of THROMBIN, or the amount of thrombin produced during or following coagulation of the blood.
Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005
Any substance that counters the effect of thrombin, an enzyme that converts fibrinogen into fibrin, leading to blood coagulation.
Mentioned in: Hypercoagulation Disorders
Gale Encyclopedia of Medicine. Copyright 2008 The Gale Group, Inc. All rights reserved.