Biological Trace Element Research

, Volume 114, Issue 1–3, pp 207–215 | Cite as

Effect of iodine supplement on iodine status and 5′-deiodinase activity in the brain of neonatal rats with iodine deficiency

  • Nianqing Liu
  • Aijun Zuo
  • Dongchun Liang
  • Zhiyong Zhang
  • Gang Guo
  • Zhifang Chai
Original Articles


The weanling Wistar rats of iodine deficiency were divided into three groups for supplementation of different levels of iodine (iodine-excessive [IE], iodine-adequate [IA], and iodine-deficient [ID]), with a control group (C). The iodine content in the thyroid was determined by epithermal neutron activation analysis. The activities of 5′-deiodinase and 5-deiodinase in the brains were assayed by determining the conversion ratios of T4 to T3 and rT3, respectively. The thyroid hormones levels in serum were also tested. The results indicated that the ID group had a goiter containing a small amount of iodine, but the IE group had a slightly swollen thyroid with rich iodine; the concentration of iodine per unit mass of thyroid was lower in group IE than in groups IA and C. The highest 5′-deiodinase and lowest 5-deiodinase activities in group ID and the lowest 5′-deiodinase activity in group IE were found. The iodine deficiency or excess resulted in a compensated hypothyroid state. The results suggest that the iodine status and the deiodinases activities would become normal for the rats of iodine deficiency if adequate iodine is supplemented soon after birth. Meanwhile, it is also critical to avoid excessive intake of iodine to reduce the risk for overcorrecting.

Index Entries

Iodine deficiency iodine excess iodine level in thyroid 5′-deiodinase thyroid hormones 


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Copyright information

© Humana Press Inc. 2006

Authors and Affiliations

  • Nianqing Liu
    • 1
  • Aijun Zuo
    • 2
  • Dongchun Liang
    • 2
  • Zhiyong Zhang
    • 1
  • Gang Guo
    • 2
  • Zhifang Chai
    • 1
  1. 1.Laboratory of Nuclear Analytical Techniques, Institute of High Energy PhysicsChinese Academy of SciencesBeijingChina
  2. 2.Tianjin Institute of EndocrinologyTianjinChina

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