The thrombolytic effect of tissue plasminogen activator depends on which of the following?
Circulating heparin
Concomitant therapy with high doses of aspirin
Factor II (prothrombin) concentration
Fibrinogen concentration
Presence of fibrin at the site of the thrombus
Correct answer
Presence of fibrin at the site of the thrombus
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correct answer: E
Activated plasminogen (plasmin) degrades fibrin to fibrin split products.
Heparin activates antithrombin III, which decreases the activity of IIa and Xa.
Aspirin inhibits cyclooxygenase and thereby prostaglandin production by platelets.
Factor II (prothrombin) is the inactive form of IIa (thrombin).
TPA action is not dependent on fibrinogen concentration.