Abstract: AIM:To investigate the regulation of DIDS on PI3K/Akt and ROS signal transduction in ischemia-reperfusion myocardial injury. METHODS: Male SD rats were randomized into four groups: sham group, I/RI (ischemia/reperfusion injury) group, CAT (catalase) group and DIDS group. Myocardial infarction size, levels of tissue ROS, myocardial apoptosis index, serum levels of creatine kinase (CK), lacate dehydrogenase (LDH), malondialdehyde (MDA) and superoxide dismutase (SOD), and the myocardial Akt and phospho-Akt protein activity of MDA and SOD, and the myocardial Akt and activity of expressions were determined. RESULTS: Compared with those in I/RI group, myocardial infarction size, apoptotic index and activity of CK and LDH significantly decreased in DIDS and CAT groups. No difference was seen between CAT group and DIDS group. Compared with those in I/RI group, MDA levels decreased and the activity of SOD increased in DIDS and CAT groups (P<0.05). The activity of SOD was higher, but the levels of MDA were lower in CAT group compared with those in DIDS group (P<0.05). Compared with those in I/RI group, the myocardial ROS levels significantly reduced in DIDS and CAT groups. ROS levels in CAT group were lower than those in DIDS group (P<0.05). No significant difference on the total Akt expression was observed among the four groups (P>0.05). Compared with those in the sham group, phospho-Akt levels were enhanced in the other three groups (P<0.05). Phospho-Akt levels were significantly higher in DIDS group compared with those in I/RI and CAT groups (P<0.05), but no significant difference was observed in the levels of phospho-Akt between I/RI group and CAT group. CONCLUSION: DIDS strongly protects cardiomyocytes against I/RI-induced apoptosis via activating PI3K/Akt signaling pathway and reducing ROS levels.