Difference in the action mechanism of radon inhalation and radon hot spring water drinking in suppression of hyperuricemia in mice

Etani, Reo*; Kataoka, Takahiro*; Kanzaki, Norie*   ; Sakoda, Akihiro   ; Tanaka, Hiroshi ; Ishimori, Yuu  ; Mitsunobu, Fumihiro*; Yamaoka, Kiyonori*

Although radon therapy is indicated for hyperuricemia, the underlying mechanisms of action have not yet been elucidated in detail. Therefore, we herein examined the inhibitory effects of radon inhalation and hot spring water drinking on potassium oxonate (PO)-induced hyperuricemia in mice. After mice inhaled radon at a concentration of 2000 Bq/m for 24 h or were given hot spring water for 2 weeks, they were administrated PO. Radon inhalation or hot spring water drinking significantly inhibited elevations in serum uric acid levels through the suppression of xanthine oxidase activity in the liver. Radon inhalation activated anti-oxidative functions in the liver and kidney. These results suggest that radon inhalation inhibits PO-induced hyperuricemia by activating anti-oxidative functions, while hot spring water drinking may suppress PO-induced elevations in serum uric acid levels through the pharmacological effects of the chemical compositions dissolved in it.