PTGS2 and myocardial ischemia: On the other hand, cyclooxygenase-2 (Cox-2), one isoform of cyclooxygenase which catalyzes the transformation of arachidonic acid to prostanoids [16], has been recognized as a protein highly expressed in the cardiac tissue during myocardial ischemia and proved to associate with the severity of apoptosis in myocardial infarction [17].