RADIOISOTOPES

In this study, we aimed to find out new indications of radon therapy and examined whether radon inhalation induced antidepressant-like effects in mice. First, we investigated the effects of radon inhalation on the forced swim stress-induced model of depression. We evaluated depression-like symptoms before and after forced swim test (FST). All mice were examined the locomotor activity and the responses to novel environments by open field test, and only depression groups performed depression-like behavior by FST. Pre-treated mice inhaled radon at background (BG) level, or at a concentration of 2,000 Bq/m³ for 24 h before FST, and post-treated mice inhaled similar levels of radon after the FST. Forced swim stress induced depression-like behavior, and 2,000 Bq/m³-radon inhalation alleviated depression-like symptoms compared to BG level concentration. Concurrently, Swim stress induced the decrease in norepinephrine and dopamine levels in brain tissue. Furthermore, swim stress-induced depression reduced superoxide dismutase activity in blood plasma and increased lipid peroxide content in brain tissue. Treatment with radon inhalation produced antidepressant-like effects, i.e., enhanced monoamines, including Serotonin, norepinephrine and dopamine levels in brain tissue, as well as depression-like behavior. These findings indicated that radon inhalation prevented and alleviated swim stress-induced depression-like symptoms in mice.