- Discussion:
 - principal metabolite of arachidonic acid in platelets;
 - stimulates platelet activation, and assists in intravascular aggregation of platelets;
 - ASA irreversibly inhibits cyclooxygenase by acetylation of serine residue at its active site;
    - cyclooxygenase must be continuously produced in endothelial cells, since they recover their ability to synthesize Prostacyclin within a 
         few hours;
    - platelets cannot produce cyclooxygenase, & thromboxane synthesis recovers only as new platelets enter circulation