Inhibitory Effects of Pre and Post Radon Inhalation on Carbon Tetrachloride-induced Oxidative Damage in Mouse Organs

Radon inhalation activates antioxidative functions in some organs of mice. We examined the prevention effects of pre radon inhalation and the alleviation effects of post radon inhalation on carbon tetrachloride (CCl4)-induced oxidative damage in the brain, heart, lung, liver, and kidney of mice. In addition, we compared the effect of pre and post radon inhalation on oxidative damage. Mice inhaled radon at a concentration of 18000Bq/m3 for 6hrs before or after CCl4 administration. As a result, the total glutathione(t-GSH) contents and catalase(CAT) activities in the brain, heart, lung, liver, and kidney and superoxide dismutase(SOD) activities in the heart and lung were significantly higher in pre and post radon-inhaled mice than in mice treated with only CCl4. Pre radon inhalation inhibited and post radon inhalation reduced lipid peroxidation induced by CCl4. In addition, there were no significant differences in lipid peroxide(LPO) levels in the brain, heart, lung, liver, and kidney between pre and post radon-inhaled mice. These findings suggested that post radon inhalation has the same effects as pre radon inhalation against CCl4-induced oxidative damage in the brain, heart, lung, liver, and kidney

Comparison of antioxidative effects between radon and thoron inhalation in mouse organs

Radon therapy has been traditionally performed globally for oxidative stress-related diseases. Many researchers have studied the beneficial effects of radon exposure in living organisms. However, the effects of thoron, a radioisotope of radon, have not been fully examined. In this study, we aimed to compare the biological effects of radon and thoron inhalation on mouse organs with a focus on oxidative stress. Male BALB/c mice were randomly divided into 15 groups: sham inhalation, radon inhalation at a dose of 500 Bq/m3 or 2000 Bq/m3, and thoron inhalation at a dose of 500 Bq/m3 or 2000 Bq/m3 were carried out. Immediately after inhalation, mouse tissues were excised for biochemical assays. The results showed a significant increase in superoxide dismutase and total glutathione, and a significant decrease in lipid peroxide following thoron inhalation under several conditions. Additionally, similar effects were observed for different doses and inhalation times between radon and thoron. Our results suggest that thoron inhalation also exerts antioxidative effects against oxidative stress in organs. However, the inhalation conditions should be carefully analyzed because of the differences in physical characteristics between radon and thoron

Effects of some physical conditions on leaching rate of radon from radioactive minerals originating from some hot springs

In order to determine the best physical conditions for leaching more radon from minerals into water, we measured the leaching rate of radon from radioactive minerals under the conditions of some different grain sizes and water temperatures. Water temperature affected the leaching rate of radon although the grain size did not significantly affect it. Furthermore, we proposed ultrasonic irradiation to the mixture of a mineral and water as the method of leaching more radon. Ultrasonic irradiation was efficient to leach more radon from the mineral soaked in water because of ultrasonic cavitation.</p

Basic Study on Activation of Antioxidation Function in Some Organs of Mice by Radon Inhalation Using New Radon Exposure Device

ラドン療法の適応症には活性酸素に由来する生活習慣病が多く，その機構の更なる解明が期待されている。また，汎用性があり医学的効果が再現できるラドン吸入装置の構築は意義が大きい。このため，著者らは共同で開発したラドン吸入試作装置を用い，マウス諸臓器中の抗酸化機能の変化特性を検討した。ラドン吸入試作装置は，特殊加工したラドン線源を収納したユニットの数量，それへの送風量及び湿度などを調節することによりラドン濃度を自在に調整可能にするものである。この装置によりマウスに400Bq/m3あるいは4000Bq/m3のラドンを吸入させた。その結果，脳・肺・肝臓・腎臓において，抗酸化系酵素であるSODとカタラーゼの両活性が増加し，過酸化脂質量が減少した。この抗酸化機能の亢進により，本実験条件でのラドン吸入は活性酸素障害の抑制，すなわち，生活習慣病の予防や症状緩和に効果のある可能性が改めて示唆できた。There are a lot of life style diseases that are related to reactive oxygen species in indications of the radon therapy, and, the further clarification of mechanism is expected. Therefore, in this study, we investigated the activation of antioxidation function in some organs of mice by radon inhalation using the new radon exposure device. It was enable that this device was the adjustments of radon concentration by changing the air flow rate to the specially processed radon source and so on. The mice were made to inhale the radon of 400Bq/m3 or 4000Bq/m3 with this device. Results show that in brain, lungs, liver, and kidney, both the activities of superoxide dismutase(SOD) and catalase increased, and lipid peroxide levels decreased. This suggests that radon inhalation enhanced the antioxidation function. These findings are important in understanding the mechanism of diseases in which radon therapy is used as treatment, and most of which are called activated oxygen-related diseases

Radioactivity and radon emanation fraction of the granites sampled at Misasa and Badgastein

The chemical composition was analyzed and the radioactivity, radon exhalation rate and emanation fraction were measured to investigate the characteristics of the granites sampled at Misasa and Badgastein, world famous for radon therapy. The Misasa granite was probably composed of quartz, albite and microcline. The Badgastein granite was probably composed of quartz and muscovite. The radon exhalation rates and emanation fractions of the Misasa granite were much higher than those of the Badgastein granite, regardless of the Ra-226 activity concentrations

Protective Effects of Radon Inhalation on Carrageenan-Induced Inflammatory Paw Edema in Mice

We assessed whether radon inhalation inhibited carrageenan-induced inflammation in mice. Carrageenan (1% v/v) was injected subcutaneously into paws of mice that had or had not inhaled approximately 2,000 Bq/m3 of radon for 24 h. Radon inhalation significantly increased superoxide dismutase (SOD) and catalase activities and significantly decreased lipid peroxide levels in mouse paws, indicating that radon inhalation activates antioxidative functions. Carrageenan administration induced paw edema and significantly increased tumor necrosis factor-alpha (TNF-α) and nitric oxide in serum. However, radon inhalation significantly reduced carrageenan-induced paw edema. Serum TNF-α levels were lower in the radon-treated mice than in sham-treated mice. In addition, SOD and catalase activities in paws were significantly higher in the radon-treated mice than in the sham-treated mice. These findings indicated that radon inhalation had anti-inflammatory effects and inhibited carrageenan-induced inflammatory paw edema

Comparative Study on the Inhibitory Effects of α-Tocopherol and Radon on Carbon Tetrachloride-Induced Renal Damage

Since the 2011 nuclear accident in Fukushima, the effects of low-dose irradiation, especially internal exposure, are at the forefront of everyone’s attention. However, low-dose radiation induced various stimulating effects such as activation of antioxidative and immune functions. In this study, we attempted to evaluate the quantitative effects of the activation of antioxidative activities in kidney induced by radon inhalation on carbon tetrachloride (CCl4)-induced renal damage. Mice were subjected to intraperitoneal (i.p.) injection of CCl4 after inhaling approximately 1000 or 2000 Bq/m3 radon for 24 h, or immediately after i.p. injection of α-tocopherol (100, 300, or 500 mg/kg bodyweight). In case of renal function, radon inhalation at a concentration of 2000 Bq/m3 has the inhibitory effects similar to α-tocopherol treatment at a dose of 300–500 mg/kg bodyweight. The activities of superoxide dismutase and catalase in kidneys were significantly higher in mice exposed to radon as compared to mice treated with CCl4 alone. These findings suggest that radon inhalation has an antioxidative effect against CCl4-induced renal damage similar to the antioxidative effects of α-tocopherol due to induction of antioxidative functions