Objective: To investigate the effect of selenium on the activities of liver type I deiodinase (IDI) in iodine-excess mice.
Methods: Forty female weanling Balb/c mice of 18-22 body weight were randomly divided into 5 groups: normal control group (N, deionized water), iodine-excess group I (IE I, 3 mg/L Iodine water), IE I + Se group (+ 1 mg/L Se water), iodine-excess group II (IE II, 5 mg/L Iodine water) and IE II + Se group (+ 1 mg/L Se water), and they were fed with standard diets and different level of iodine and selenium water for 12 weeks.
Results: Iodine-excess groups show diffused colloid goiter; Serum TT4 of two iodine-excess groups were significantly higher than Normal control, and TT3 of IE II decreased significantly; The selenium level and IDI activity of mice liver was decreased significantly in iodine-excess group, but no difference between IE I and IE II.
Conclusion: Iodine-excess intake can decrease the selenium level and IDI activity of mice liver, which maybe is the reason to increase the serum TT4 level and lead to goiter, and selenium can alleviate that.