MAPK3 and myocardial infarction: In that study the administration of urocortin specifically at the time of myocardial reperfusion reduced MI size and increased the phosphorylation of myocardial Erk1/2, the effects of which were abrogated by the co-administration of the pharmacological MEK1/2-Erk1/2 inhibitor, PD98059, at the time of reperfusion [218].