Increasing evidence has shown that oxidative stress can promote the development of DCM.19 The antioxidative stress effect of H2S has an important role in the functions of H2S.30, 31, 32, 33 It has been reported that H2S could suppress ROS production34 and increase SOD activity in cardiomyocytes.35 Our study demonstrated that exogenous H2S could suppress the production of ROS in the hearts of db/db mice. The gene discussed is SOD1; the disease is familial dilated cardiomyopathy.