SOD1 and diabetes mellitus: As shown in Figure 7, a significant rise was found in MDA contents of spinal cord at 5 weeks after STZ-induced diabetes (Figure 7(b), P < 0.001, Dia vs. saline) accompanied by reduced activities of SOD and GSH-Px (Figures 7(a) and 7(c), P < 0.001, Dia vs. saline).