RESUMO
BACKGROUND: Experimental data suggest that matrix metalloproteinases (MMPs) such as MMP-3 have a central role in the remodeling period after a myocardial infarction (MI). The aim of this study was to use an experimental small-animal model to investigate the fluctuation in MMP-3 levels occurring in vivo after an acute MI. METHODS: We studied 13 New Zealand white rabbits weighing between 3 and 4 kg. After anesthetizing the animals, we performed a tracheotomy and induced an acute MI in 10 of the animals by occluding the left anterior descending coronary artery for 45 minutes. The remaining 3 rabbits constituted the control group. Three hours after reperfusion, blood samples were taken for biomedical analyses. RESULTS: Three hours after the artificially induced acute MI, serum MMP-3 levels were decreased by almost 50%. Cardiac troponin I (cTnI) concentrations were increased greatly (90-fold) after MI, further validating the efficiency of our experimental in vivo model of acute MI. CONCLUSION: Combining the data, we demonstrated that acute MI caused an early reduction in MMP-3 levels. The range of MMP-3 reduction is limited compared with other factors predicting MI, such as cTnI, which increases its usefulness. We demonstrated, however, that plasma fluctuation in MMP-3 levels could be used as a supplementary independent predictor of cardiovascular events in patients with stable coronary artery disease. This acute MI model used in our controlled setting proved to be a reliable and safe method for conducting in vivo studies.