Basic study on suppression effects of active oxygen diseases by radon inhalation and its mechanism

Kataoka, Takahiro*; Kanzaki, Norie   ; Sakoda, Akihiro   ; Ishida, Tsuyoshi; Tanaka, Hiroshi ; Hanamoto, Katsumi*; Terato, Hiroaki*; Mitsunobu, Fumihiro*; Yamaoka, Kiyonori*

We have reported that radon inhalation inhibits oxidative induced damages in some mouse organs due to activation of antioxidant functions. These activations are probably induced by reactive oxygen species following radon inhalation. In this study, we assayed the production of hydrogen peroxide and antioxidant associated substances in brain, lung, heart, liver, stomach, pancreas, kidney, small intestine, and colon in mouse after radon inhalation (1,000 or 10,000 Bq/m for 24 hours). Results showed that radon inhalation significantly decreased LPO levels in liver (1,000 Bq/m and 10,000 Bq/m) and heart (1,000 Bq/m), suggesting that radon inhalation inhibits oxidative stress. However, On the other hand, radon inhalation at a concentration of 10,000 Bq/m significantly increased the levels of LPO and hydrogen peroxide in lungs only. These findings suggested that radon inhalation at high concentration does not induce oxidative stress in other organs except lung.