[Mondoshawan]

Heparin binds to Antithrombin III (ATIII) and dramatically accelerates its enzymatic activity. As a serine protease inhibitor, ATIII-heparin can inactivate the serine proteases of the intrinsic pathway, XIIIa, XIa, IXa, and Xa - but what is its primary anti-coagulative activity?

• ATIII stimulates the release of plasminogen activators from tissues
• Activated ATIII dissolves the cross-linking of fibrin by proteolysis
• ATIII catalyses the binding of thrombin to thrombomodulin, allowing Protein C to be activated
• One molecule of ATIII inactivates one molecule of thrombin; heparin is catalytic
• Plasmin is cleaved from plasminogen by ATIII

 

[medico.in]

i think it is c

c is my ans

 

[doc_study]

D.

One molecule of ATIII inactivates one molecule of thrombin; heparin is catalytic

 

[aktorque]

D) One molecule of ATIII inactivates one molecule of thrombin; heparin is catalytic

My ans is D) One molecule of ATIII inactivates one molecule of thrombin; heparin is catalytic.

heparin-AT complex mainly acts on intrinsic pathway of coagulation, especially on factors XIIIa, XIa, IXa, and Xa. Heparin binds on AT-III to activates the inhibitory effect on the clotting factors.

"One molecule of ATIII inactivates one molecule of thrombin" .... I don't know anything about the ratio...

 

[salz]

My answer C

 

[apx85]

D

D) ATIII binds directly to Thrombin and inactivates it. Heparin catalyzes this function

 

[Mondoshawan]

Correct!

D is correct: one molecule of ATIII inactivates one molecule of thrombin; heparin is catalytic, and can quickly bind to another ATIII.

• Bradykinin and thrombin, among other agents, stimulate the release of plasminogen activators from tissues (A).
• Fibrin is digested by plasmin (B).
• ATIII does not catalyse the binding of thrombin to thrombomodulin (C); however, thrombin does activate Protein C, and this is greatly enhanced with thrombomodulin.
• Plasminogen activators convert plasminogen to active plasmin (E).