Evaluation of hydrogen peroxide induced oxidative stress by radon inhalation in mouse organs

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

We have reported that radon inhalation activates antioxidative functions in mouse organs. These activation inhibits reactive oxygen species (ROS) induced oxidative stresses. Activation of antioxidative functions induced by radon inhalation probably due to the production of a small quantity of ROS. However, there were no reports on this mechanism. In this study, we evaluated hydrogen peroxide induced oxidative stress by radon inhalation in mouse organs. That is, mice inhaled radon at a concentration of 1 kBq/m or 10 kBq/m for 24 hours. Results showed that radon inhalation increased hydrogen peroxide in liver and lung by 20%. On the other hand, hydrogen peroxide in heart decreased by 20%. This is probably due to total glutathione reacts with hydrogen peroxide. These findings suggest that radon inhalation produces a small quantity of hydrogen peroxide, which is ROS, in mouse organs. However, antioxidative related substances, which are catalase and total glutathione, play an important role to reduce oxidative stress.