Aspirin Effect on TxA2
Single
200 mg dose destroys 90% of cyclo-oxygenase
In platelet :
Since platelets lack a nucleus they can’t synthesize new cyclo-oxygenase so effects are
irreversible
Takes 7 – 10 days for effects of aspirin to be removed as new platelets need to replace old
platelets
platelet cyclo-oxygenase more sensitive to aspirin than endothelial cyclo-oxygenase so
low-dose aspirin inhibits platelet cyclo-oxygenase more than endothelial cell
In endothelial
cell :
Single
200 mg dose destroys 90% of cyclo-oxygenase
Since endothelial cells have a nucleus they can synthesize new cyclo-oxygenase so
effects are reversible