Iodine Deficiency And Iodine Supplement

In order to studied the effects of iodine supplement to iodine deficient rats, we reconstructed animal model, rats, with iodine deficiency, and gave them different amounts of iodione diets after birth, which were divided into 4 groups at age of 20-day by the uptake of iodine-nutrition, ie low-, appropriate- and high iodine groups (LI, AI, HI) and control (N) separately. Then the serum-thyroid hormone assay, the kinetic analysis of T₃ receptor in the brain, activity of T₄ 5'-and 5-deiodinase within brain, and the subcellular some elements(including trace elements) distribution in brain cells, were determind at 20 days age.On serum [TT₃], there were no significant difference among these 4 groups, but a slightly decrease in LI group. In LI and HI groups, [FT₃] were significantly higher than that of control. Both LI and HI group had decreased [TT₄] and [FT₄] level than that of control (P<0.05). The brain and synapse membrane thyroid hormone receptor MBC in LI, AI and HI group were all significantly augmentor than that of control. The Ka of T₃ receptor in various groups were nearly similar (p>0.05). In LI group, the activity of T₄ 5'-deiodinase is significantly more than that of N group (P<0.05), and the activity of 5-deiodinase is significantly less than that of N group(P<0.05). In HI group the activities of both T₄ 5'-and 5-deiodinase are significantly less than that of N group (P<0.05).T₃R MBC was higher in LI group than that in normal group suggested that the elevation of T₃R MBC might be a compensation for iodine-deficiency so with hypothyroidism. We detected that after being iodine deficiency Iodine-induced hyperthyroidism could appeared when supplied with appropriate iodine and a iodine-induced hypothyroidism could occurred when iodine excess debases.