Significance of matrix metalloproteinase-9 in cardiac dysfunction during the very acute phase after myocardial infarction in hamsters

Matrix metalloproteinase-9 activity is dramatically increased during the acute phase after myocardial infarction. However, the relationship between matrix metalloproteinase-9 activity and cardiac dysfunction is unclear. In 1-day post-myocardial infarction hamsters, matrix metalloproteinase-9 activity was significantly increased, while matrix metalloproteinase-2 activity was not increased. A selective matrix metalloproteinase inhibitor, [2S,4S]-N-Hydroxy-5-ethoxymethyloxy-2-methyl-4-[4-phenoxybenzoyl] aminopentanamide (ONO-4817), significantly suppressed matrix metalloproteinase-9 activity 1 day after myocardial infarction. ONO-4817 also significantly prevented the development of cardiac dysfunction and left-ventricular dilatation. Matrix metalloproteinase-9 might play a crucial role in cardiac dysfunction and left-ventricular dilatation during the very acute phase after myocardial infarction.