Posts: 3,675,934
Threads: 734,342
Joined:
Sep 2021
Reputation:
5
A young man with hypercholesterolemia is rushed to the hospital
with crushing chest pain radiating to his left arm and a probable heart
attack. Which of the following treatments should be considered?
a. A platelet transfusion
b. Heparin infusion
c. Thrombin infusion
d. Fibrinogen infusion
e. Tissue plasminogen activator infusion
Posts: 3,675,934
Threads: 734,342
Joined:
Sep 2021
Reputation:
5
Many enzymes interact to regulate blood clotting.
Plasmin is activated by proteolytic cleavage of its zymogen, plasminogen.
The activating protease is called tissue plasminogen activator (tPA).
Plasmin hydrolyzes fibrin clots to form soluble products, and is used to dissolve
clots in coronary arteries that cause myocardial infarction. Platelets,
thrombin, and fibrinogen promote clotting through the intrinsic pathway
and would be contraindicated in myocardial infarction. Platelets form a
plug at the site of bleeding and bind prothrombin to facilitate its conversion
to thrombin. Fibrinogen is the substrate acted upon by thrombin to
yield the fibrin mesh of blood clots. Heparin is a mucopolysaccharide that
terminates clot formation by interfering with a number of steps in the coagulation
cascade. Heparin inhibits the formation of clots, but cannot dissolve
clots that have already formed.
