Study of the response of superoxide dismutase in mouse organsto radon using a new large-scale facility forex posing small animals to radon

We examined dose-dependent or dose rate-dependent changes of superoxide dismutase (sod) activity using a new large-scale facility for exposing small animals to radon. mice were exposed to radon at a concentration of 250,500,1000,2000,or 4000 bq/m 3 for 0.5,1,2,4,or 8 days. when mice were exposed to radon at 2000 day•bq/m 3,activation of sod activities in plasma,liver,pancreas,heart,thymus,and kidney showed dose-rate effects. our results also suggested that continuous exposure to radon increased sod activity,but sod activity transiently returned to normal levels at around 2 days. moreover,we classified the organs into four groups (1. plasma,brain,lung; 2. heart,liver,pancreas,small intestine; 3. kidney,thymus; 4. stomach) based on changes in sod activity. thymus had the highest responsiveness and stomach had lowest. these data provide useful baseline measurements for future studies on radon effects.