Study of the Response of Superoxide Dismutase in Mouse Organs to Radon Using a New Large-scale Facility for Exposing Small Animals to Radon

• Published in: JOURNAL OF RADIATION RESEARCH 2011, Vol.52 (6), p.775-781
• Main Authors: Kataoka, Takahiro, Sakoda, Akihiro, Ishimori, Yuu, Toyota, Teruaki, Nishiyama, Yuichi, Tanaka, Hiroshi, Mitsunobu, Fumihiro, Yamaoka, Kiyonori
• Format: Article
• Language: English
• Subjects: Animals; Antioxidants - metabolism; Dose-Response Relationship, Radiation; Male; Mice; Mice, Inbred BALB C; Organ Specificity; Radon - administration & dosage; Radon - therapeutic use; Superoxide Dismutase - metabolism; Superoxide Dismutase - radiation effects; Superoxides; Technology, Radiologic - instrumentation
• ISSN: 0449-3060; 1349-9157; 1349-9157
• DOI: 10.1269/jrr.10072

We examined dose-dependent or dose rate-dependent changes of superoxide dismutase (SOD) activity using a new large-scale facility for exposing small animals to radon. Mice were exposed to radon at a concentration of 250, 500, 1000, 2000, or 4000 Bq/m3 for 0.5, 1, 2, 4, or 8 days. When mice were exposed to radon at 2000 day・Bq/m3, activation of SOD activities in plasma, liver, pancreas, heart, thymus, and kidney showed dose-rate effects. Our results also suggested that continuous exposure to radon increased SOD activity, but SOD activity transiently returned to normal levels at around 2 days. Moreover, we classified the organs into four groups (1. plasma, brain, lung; 2. heart, liver, pancreas, small intestine; 3. kidney, thymus; 4. stomach) based on changes in SOD activity. Thymus had the highest responsiveness and stomach had lowest. These data provide useful baseline measurements for future studies on radon effects. 「INTRODUCTION」Low-dose X- or γ-irradiation induces various effects, especially activation of biological defense system, including antioxidative1-5) and immune functions. 6, 7)