Changes of SOD-like substances in mouse organs after low-dose X-ray irradiation.

We demonstrated that low-dose irradiation with 50 cGy of X-ray induces in vivo production of superoxide dismutase (SOD)-like substances and accelerates antioxidant activity. To elucidate the defense mechanism against X-ray radiation, we examined which components among these SOD-like substances, such as SOD, vitamin C and celuroplasmin, are produced by low-dose irradiation. Our study revealed that SOD-like specific activity hardly involved SOD-like substances other than SOD. Moreover, it is suggested that low-dose irradiation induced synthesis and production of SOD itself, leading to elevation of SOD-specific activity.