In this study, we found that when myocardial ischemic injury occurred in DM rats or cells treated with high glucose, upregulation of Nrf2 and Drp1 protein levels, contents of myocardial injury markers (LDH, CK-MB, and cTnI), and contents of oxidative stress products (MDA and ROS) was identified, while the activity of antioxidant SOD was decreased. The gene discussed is SOD1; the disease is diabetes mellitus.