EDN1 and myocardial infarction: Furthermore, although it has been established that cardiac injury, such as in hypoxemia/reperfusion or myocardial infarction, sharply augments cardiac NGF [7], [12], [13], nothing is known of the ligands and cell-surface recepor(s) that trigger NGF upregulation, except for endothelin-1, which regulates NGF expression in cardiomycytes [8].