FIGURE 5.

Model comparing the effects of aspirin in platelets vs the vasculature. A, Aspirin’s action in platelets, that is mimicked in p-COX-1-ko mice, results in the inhibition of COX-1-dependent pro-thrombotic eicosanoids, including TxA₂, PGE₂, and PGF_2α, and in a beneficial antithrombotic effect. B, In the vasculature, aspirin blocks the activity of COX-1 and COX-2 and the synthesis of antithrombotic and vasorelaxant mediators, including PGI₂ and PGD₂. This effect favors thrombosis thus countering and limiting the beneficial effects of aspirin on the cardiovascular system mediated through inhibition of COX-1 in platelets. This figure was produced using Servier Medical Art (http://www.servier.com)