The influence on myocardial infarct size, plasma myocardial enzyme and hemodynamics of ischemia postconditioning in mice model

Objective: To evaluate the influence on the myocardial-reperfusion injury of ischemia postconditioning in mice model and provide an experimental evidence of cardiacprotective function after emergency ischemic myocardial events in clinics. Methods: Sixty male adult KM mice were randomly divided into three different groups: ischemia postconditioning,ischemia-reperfusion and sham operation, 20 mice in each group. Postconditioning group undergone open-chest surgery to induce left coronary artery 45 min occlusion and reperfused for 3 h, after LCA occlusion, 3 cycles of 10 s reperfusion followed by 10 s LCA reocclusion were applied during the early minutes of reperfusion. Ischemic size and Infarct size were measured by Evans blue and TTC staining respectively, assessed and evaluate the level of plasma CK,LDH, AST and hemodynamics of different groups. Results: Infarct size was smaller in postconditioning group than in I/R Control (P0.05). The level of plasma CK, LDH and AST were decreased and hemodynamic measurement of MAP, LVSP, dp/dtmax, dp/dtmin and LVEDP were improved by postconditioning (P0.05). Conclusions: Ischemia postconditioning at onset of reperfusion can obviously reduce mice myocardial infarct size, decrease the level of plasm myocardial enzyme and improve the level of hemodynamics.