Intervention of selenium on the activity of iodothyronine 5'-and 5-deiodinase in the cerebrum of filial mice with iodine excess

Objective To study the influence of iodine excess intake on the activity of iodothyronine 5'-and 5-deiodinase in the cerebrum of filial mice and the effect of selenium intervention.Methods Sixty Balb/c mice were divided randomly into four groups with different drinking water.They were control group, iodine excess group (3000 μg/L I),selenium supplementation group (200 μg/L Se),and iodine excess plus selenium group (3000 μg/L I and 200 μg/L Se). At the end of the fourth month, the mice were mated. Serum TT4, TT3 , rT3 and TSH of the progenies were determined on postnatal day 14 and 28. Activities of T4 5'-deiodinase and 5-deiodinase in the cerebrum of filial mice were measured too. Results On postnatal day 14, serum TT4 level was lower, and serum TSH was significantly higher in the iodine excess group than the control group and higher than the iodine excess plus selenium group. On postnatal day 28, no significance in serum TT4,TT3 and TSH level among the four groups. On postnatal day 0 and 14, iodothyronine 5'-deiodinase activities in the cerebrum of the progenies in the iodine excess group were significantly higher than those in the control group , while the iodine excess plus selenium group were lower than those in the iodine excess group (P0.05); iodothyronine 5-deiodinase activity in the excess iodine group was significantly lower than those in the control group (P0.05), while the iodine excess plus selenium group was higher than those in the iodine excess group (P0.05). Conclusions Iodine excess intake can change the activities of iodothyronine 5'-and 5-deiodinase in the cerebrum of filial mice and selenium supplementation might have some favorable effects.