In order to further evaluate the redox system state the possible role of mitochondrial ROS in burn-induced ARF, the total SOD activity and the protein expression and activity of MnSOD were detected and the data showed that total SOD activity reduced (49.0±2.8 U/mg protein vs. 71.3±3.4 U/mg protein in sham-burned group, P<0.05) at 3 h after burn injury, continued to decrease until 24 h postburn (32.7±3.9 U/mg protein), and remained at low level thereafter (Fig. 4C). Here, SOD1 is linked to acute kidney injury.