reduced skin ROS and MDA concentration in vivo . Rats were irradiated to the buttock skin with a single dose of 45 Gy electron beams followed by an injection of PBS, SOD1 or TAT-SOD1. (A) The ROS generation in rat skin tissues of indicated groups 24 h after 45 Gy electron beam irradiation. The basic ROS level of the control group was arbitrarily set as 100%. (B) Relative MDA concentration in rat skin tissues of indicated groups 3 days after 45 Gy electron beam irradiation. *P < 0.05; **P < 0.01, compared with PBS-injected control groups.