Abstract:Objective To investigate the protective role of oxiracetam in rats after myocardial ischemia-reperfusion injury (MI/RI) and its underlying mechanism. Methods A total of 32 Sprague-Dawley (SD) rats were randomly divided into 4 groups, with 8 rats in each group, that is, sham operation group (Sham group), MI/RI group, and low- and high-dose groups (30 and 50 mg/kg oxiracetam respectively). In addition to normal feeding before surgery, the rats from the two treatment groups were given the corresponding dose of oxiracetam by gavage for once per day for 7 consecutive days. Then the anterior descending coronary artery was ligated in the rats of the latter 3 groups to establish the MI/RI model. Serum contents of lactate creatine kinase isoenzyme MB (CK-MB), lactate dehydrogenase (LDH), interleukin-6 (IL-6), superoxide dismutase (SOD) and malondialldehyde (MDA) were measured with enzyme linked immunosorbent assay (ELISA). The percentage of myocardial infarction area, apoptosis rate of myocytes and the ratio of Bcl-2/Bax in myocardial tissue were measured and calculated. SPSS statistics 21.0 was used for statistical analysis. One-way ANOVA was employed for inter-group comparisons. Results The low- and high-dose groups had significantly lower percentage of myocardial infarction area (13.6% vs 22.3% vs 36.2%), apoptosis rate of myocytes (30.6% vs 21.3% vs 45.4%), and serum contents of CK-MB [(75.24±5.62) vs (63.10±7.23) vs (97.50±8.54)U/L], LDH [(660.62±49.84) vs (577.37±54.09) vs (900.02±57.74)U/L], MDA [(66.47±6.25) vs (57.08±4.99) vs (88.84±3.26)U/L] and IL-6 [(153.34±6.81) vs (143.31±9.08) vs (186.39±10.18)pg/ml], but obviously elevated serum SOD content [(24.80±3.32) vs (34.82±3.66) vs (15.22±1.24)U/ml] and Bcl-2/Bax ratio (0.47 vs 1.16 vs 0.19) when compared with the MI/RI group (all P<0.05). Conclusion Oxiracetam can protect MI/RI by attenuating oxidant stress response and suppressing mitochondrial pathway of apoptosis.