Advertisement

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

Abstract

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 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    J. S. Chen and H. Y. Wu, Fortification of salt with iodine, International Life Sciences Institute Regional Conference on Food Fortification: Science, Technology, and Policy, Food Nutr. Bull. 19 (2) (1998).Google Scholar
  2. 2.
    M. Hufner, Thyroid hormones in the treatment of iodine deficiency goiter. Superfluous like goiter? MMW Fortschr. Med. 144(9), 26–29 (2002).PubMedGoogle Scholar
  3. 3.
    F. Delange, Neonatal hypothyroidism: recent developments, Baillieres Clin. Endocrinol. Metab 2(3), 637–652 (1988).PubMedCrossRefGoogle Scholar
  4. 4.
    N. Koibuchi and W. W. Chin, Thyroid hormone action and brain development, Trends Endocrinol. Metab. 11(4), 123–128 (2000).PubMedCrossRefGoogle Scholar
  5. 5.
    F. Delange, H. Burgi, Z. P. Chen, et al., World status of monitoring iodine deficiency disorders control programs, Thyroid 12(10), 915–924 (2002).PubMedCrossRefGoogle Scholar
  6. 6.
    F. Delange, B. de Benoist, and D. Alnwick, Risks of iodien-induced hyperthyroidism after correction of I deficiency by iodized salt, Thyroid 9(6), 545–556 (1999).PubMedCrossRefGoogle Scholar
  7. 7.
    J. R. Arthur and G. Beckett, Thyroid function, Br. Med. Bull. 55(3), 658–668 (1999).PubMedCrossRefGoogle Scholar
  8. 8.
    X. L. Hou, K. Wang, and Z. F. Chai, Epithermal neutron activation analytical and its application in the miniature neutron source reactor, J Radional. Nucl. Chem. 210(1), 137–148 (1996).CrossRefGoogle Scholar
  9. 9.
    Committee on Standards for Nutritional Studies. Report of the American Institute of Nutrition Ad hoc Committee on Standards for Nutritional Studies, J. Nutr. 107, 1340–1348 (1977).Google Scholar
  10. 10.
    I. J. Chopra, A study of extrathyroidal conversion of thyroxine (T4) to 3,3′,5′-triiodothyronine (T3) in vitro, Endocrinology 101, 453–463 (1977).PubMedCrossRefGoogle Scholar
  11. 11.
    R. R. Cavalieri, L. A. Gavin, F. Bui, et al., Conversion of thyroxine to 3,3′,5′-triiodothyronine (reverse-T3) by a soluble enzyme system of rat liver, Biochem. Biophys. Res. Commun. 79(3), 897–902 (1977).PubMedCrossRefGoogle Scholar
  12. 12.
    E. A. Jannini, E. Carosa, F. M. Graziano, et al., Iodine deficiency diseases and pregnancy Minerva, Endocrinology 19(3), 149–154 (1994).Google Scholar
  13. 13.
    N. Q. Liu, Q. Xu, X. L. Hou, et al., Correlation analyses between trace elements and thyroid hormone of cretinism Rats, Brain Res. Bull. 55(2), 309–312 (2001).PubMedCrossRefGoogle Scholar
  14. 14.
    A. J. Zuo, X. Q. Zhao, D. C. Liang, et al., Influence of iodine supplement on thyroid hormone receptor in brain of I deficiency rats. Chin. J. Endocrinol. 23(3), 198–200 (2004).Google Scholar
  15. 15.
    G. F. Ana, J. E. Maria, R. Estrella, et al., Expression of type 2 iodothyronine deiodinase in hypothyroid rat brain indicates an important role of thyroid hormone in the development of specific primary sensory systems, J. Neurosci. 19(9), 3430–3439 (1999).Google Scholar
  16. 16.
    M. J. Berry, L. Banu, and P. R. Larsen, Type I iodothyronine deiodinase is a selenocysteine-containing enzyme, Nature 349, 438–440 (1991).PubMedCrossRefGoogle Scholar
  17. 17.
    D. Salvatore, T. Bartha, J. W. Harney, et al., Molecular biological and biochemical characterization of the human type 2 selenodeiodinase, Edocrinology 137(7), 3308–3315 (1996).CrossRefGoogle Scholar
  18. 18.
    M. Ramauge, S. Pallud, A. Esfandiari, et al., Evidence that type III iodothyronine deiodinase in rat astrocyte is a selenoprotein, Endocrinology 137(7), 3021–3025 (1996).PubMedCrossRefGoogle Scholar
  19. 19.
    K. B. Markou, P. Paraskevopoulou, K. S. Karaiskos, et al., Hyperthyrotropinemia during iodide administration in normal children and in children born with neonatal transient hypothyroidism, J. Clin. Endocrinol. Metab. 88(2), 617–621 (2003).PubMedCrossRefGoogle Scholar
  20. 20.
    F. Delange, The role of I in brain development, Proceed. Nutr. Soc. 59, 75–79 (2000).Google Scholar
  21. 21.
    A. W. Kung, T. T. Lao, M. T. Chau, et al., Goitrogenesis during pregnancy and neonatal hypothyroxinaemia in a borderline I sufficient area, Clin. Endocrinol. (Oxf.) 53(6), 725–731 (2000).CrossRefGoogle Scholar
  22. 22.
    F. Calaciura, G. Mendorla, M. Distefano, et al., Childhood IQ measurements in infants with transient neonatal hypothyroidism, Clin. Endocrinol. (Oxf.) 43(4), 473–477 (1995).Google Scholar
  23. 23.
    Van Vliet, G. Neonatal hypothyroidism: treatment and outcome, Phyroid 9, 79–84 (1999).Google Scholar
  24. 24.
    I. B. Pedersen, N. Knudsen, T. Jørgensen, et al., Large differences in incidences of overt hyper- and hypothyroidism associated with a small difference in I intake: a prospective comparative register-based population survey, J. Clin. Endocrinol. Metab. 87(10), 4462–4469 (2002).CrossRefGoogle Scholar

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

Personalised recommendations