anticoagulant
(noun)
A substance that prevents coagulation; that is, it stops blood from clotting.
Examples of anticoagulant in the following topics:
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Anticoagulants
- An anticoagulant is a substance that prevents coagulation (clotting) of blood.
- Coumadins such as warfarin are oral anticoagulant pharmaceuticals that antagonize the effects of vitamin K1.
- It takes at least 48 to 72 hours for the anticoagulant effect to develop.
- Oral anticoagulants are used widely as poisons for mammalian pests, especially rodents.
- Another type of anticoagulant is the direct thrombin inhibitor.
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Blood Plasma
- Normally, anticoagulants and fibrinolytics in the plasma, such as plasmin and heparin, break up fibrin clots and inactivate thrombin.
- However, during endothelial injury, damaged cells will release tissue factor, another type of clotting factor that causes a cascade of thrombin production that will overpower the anticoagulants and cause a clotting response.
- Two tubes of EDTA-anticoagulated blood.
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Fibrinolysis
- Clots may also be prevented or kept from worsening through the use of blood thinners (anticoagulants).
- Aspirin has anticoagulant properties because it inhibits cyoclo-oxygenase dependent pathways of platelet activation, which can prevent clotting from worsening.
- Heparin is a fast-acting anticoagulant produced by the body and used as a drug which inhibits the activity of thrombin.
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Role of Vitamin K
- Vitamin K also synthesizes Protein C, Protein S, and Protein Z, anticoagulant proteins that degrade specific coagulation factors, preventing excessive thrombosis following the initial coagulation cascade.
- Vitamin K can be inhibited by the anticoagulant drug warfarin, which acts as an antagonist for vitamin K.
- Calcium is also required to to synthesize the anticoagulant Protein C (along with vitamin K).
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Coagulation
- It also activates more factor V, which later acts as an anticoagulant with inhibitor protein C, and factor XIII, which covalently bonds to fibrin to strengthen its attachment to the platelets.
- Many anticoagulants prevent unnecessary coagulation, and those that genetically lack the ability to produce these molecules will be more susceptible to coagulation.
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Withdrawing Blood
- The purple tube contains EDTA, an anticoagulant, and is typically used for a complete blood count.
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Complete Blood Count
- A phlebotomist collects the sample, drawing the blood into a test tube containing an anticoagulant (EDTA, sometimes citrate) to stop it from clotting.
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Heart Valve Disorders
- In individuals who require an artificial heart valve, consideration must be made for deterioration of the valve over time (for bioprosthetic valves) versus the risks of anticoagulation during pregnancy.
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Physical Characteristics and Volume
- Two tubes of EDTA-anticoagulated blood.
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Components of Blood
- Two tubes of EDTA-anticoagulated blood.