en Radiation Biology Radiation Biology تحقيق بديع Original Research <span style="font-weight: bold">Background: </span>The aim of this study was to analyze the effects of thoron and thermal treatment for aging-related diseases in humans. <span style="font-weight: bold">Materials and Methods:</span> All subjects inhaled thoron with a high concentration (about 4900 Bq/m3) for 2 weeks. Blood pressures were measured and blood samples were collected after each treatment 1, 2 and 3 weeks after the first treatment. <span style="font-weight: bold">Results:</span> The α-atrial natriuretic peptide level of the rheumatoid arthritis group was increased and the blood pressure was significantly decreased. Superoxide dismutase activity of rheumatoid arthritis group was significantly increased by treatment. In addition, thoron and thermal treatment significantly enhanced the concanavalin A-induced mitogen response and increased the level of CD4-positive cells it decreased the level of CD8-positive cells. The results suggest that thoron and thermal treatment activates antioxidative function. Furthermore, these findings suggest that thoron and thermal treatment prevents diabetic ketoacidosis and contributes to the prevention of aging-related diseases. <span style="font-weight: bold">Conclusion:</span> Thoron and thermal therapy may be part of the mechanism for the alleviation of diabetes mellitus and rheumatoid arthritis. <span style="font-weight: bold">Iran. J. Radiat. Res., 2012 9(4): 221-229 </span> Thoron and thermal treatment, health effect, diabetes mellitus, rheumatoid arthritis, antioxidant function 221 229 http://ijrr.com/browse.php?a_code=A-10-1-406&slc_lang=en&sid=1 Y. Aoyama 790031947532846002448 790031947532846002448 No T. Kataoka 790031947532846002449 790031947532846002449 No S.H. Nakagawa 790031947532846002450 790031947532846002450 No A. Sakoda 790031947532846002451 790031947532846002451 No Y. Ishimori 790031947532846002452 790031947532846002452 No F. Mitsunobu 790031947532846002453 790031947532846002453 No K. Yamaoka yamaoka@md.okayama-u.ac.jp 790031947532846002454 790031947532846002454 Yes