Suppression of dextran sulfate sodium-induced colitis in mice by radon inhalation.
The enhanced release of reactive oxygen species from activated neutrophils plays important role in the pathogenesis of inflammatory bowel disease. We previously reported that radon inhalation activates antioxidative functions in various organs of mice. In this study, we examined the protective effects of radon inhalation on dextran sulfate sodium- (DSS) induced colitis in mice which were subjected to DSS for 7 days. Mice were continuously treated with air only (sham) or radon at a concentration of 2000 Bq/m³ from a day before DSS administration to the end of colitis induction. In the results, radon inhalation suppressed the elevation of the disease activity index score and histological damage score induced by DSS. Based on the changes in tumor necrosis factor-alpha in plasma and myeloperoxidase activity in the colon, it was shown that radon inhalation suppressed DSS-induced colonic inflammation. Moreover, radon inhalation suppressed lipid peroxidation of the colon induced by DSS. The antioxidant level (superoxide dismutase and total glutathione) in the colon after DSS administration was significantly higher in mice treated with radon than with the sham. These results suggested that radon inhalation suppressed DSS-induced colitis through the enhancement of antioxidative functions in the colon.
Graduate School of Health Sciences, Okayama University, 5-1 Shikata-cho 2-chome, Kita-ku, Okayama-shi, Okayama 700-8558, Japan.
Yuichi
Y
Nishiyama
Takahiro
T
Kataoka
Keiko
K
Yamato
Takehito
T
Taguchi
Kiyonori
K
Yamaoka
D000280:Administration, Inhalation; D000818:Animals; D003092:Colitis / Q000139:chemically induced / Q000378:metabolism / Q000473:pathology / Q000532:radiotherapy*; D016264:Dextran Sulfate; D015212:Inflammatory Bowel Diseases / Q000532:radiotherapy; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009195:Peroxidase / Q000378:metabolism; D011886:Radon / Q000008:administration & dosage*; D017382:Reactive Oxygen Species / Q000378:metabolism
D017382:Reactive Oxygen Species; D016264:Dextran Sulfate; D009195:Peroxidase; D011886:Radon