The endothelial nitric oxide synthase cofactor tetrahydrobiopterin shields the remote myocardium from apoptosis after experimental myocardial infarction in vivo.

Background: Following myocardial infarction (MI), apoptosis occurs early in the remote myocardium and contributes to the processes of myocardial remodelling. Increased nitrosative stress is a well-known and potent inductor of myocardial apopto¬sis. Excess activation of endothelial nitric oxide synthase (eNOS) increases its uncoupling potential and results in nitrosative stress via formation of peroxynitrite.