Effect of Long Term Excessive Iodine Intake on Thyroid Function and Oxidative Stress in Euthyroid and Hypothyroid Rats | ||||
| Bulletin of Egyptian Society for Physiological Sciences | ||||
| Article 5, Volume 30, Issue 2, June 2010, Page 65-86 PDF (319.11 K) | ||||
| Document Type: Original Article | ||||
| DOI: 10.21608/besps.2010.36299 | ||||
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| Authors | ||||
| Amr Abbas* 1; Abd El-Aziz Hussein1; Gehan El Wakil1; Ayman Elsamanoudy2; Aza Abd El Aziz3 | ||||
| 1Department of Medical Physiology, Faculty of Medicine, Mansoura University, Egypt | ||||
| 2Department of Medical Biochemistry , Faculty of Medicine, Mansoura University, Egypt | ||||
| 3Department of Pathology, Faculty of Medicine, Mansoura University, Egypt | ||||
| Abstract | ||||
| Background and aim of work: The aim of the current study was to investigate the effects of long term excessive iodine intake on gene expression of thyroidal sodium iodide symporter (NIS), D1 deiodinase and thyroid peroxidase (TPO), thyroid hormones, oxidative injury and anti-oxidative ability of euthyroid and hypothyroid Sprague Dawley rats. Materials and Methods: Ninety rats were divided into euthyroid and hypothyroid (thiocyanate induced) groups with or without administration of excess iodine (3000 or 6000 μg/l) for 4 weeks. Serum thyroxine (T4), triiodothyronine (T3), TSH, thyroid antioxidants ((glutathione S transferase, catalase, superoxide dismutase enzymes, nitric oxide and total antioxidants), lipid peroxide (malondialdehyde, MDA) were measured. RT-PCR gene expression for thyroidal NIS, D1 deiodinase and TPO were performed. Results: Thiocyanate significantly decreased thyroid hormones (T3, T4), increased lipid peroxides and antioxidants, increased gene expression of NIS, D1 deiodinase, TPO. High iodine intake to hypothyroid rats significantly decreased NIS, D1 deiodinase and TPO genes expression. Excess iodine significantly increased MDA and antioxidants in euthyroid and hypothyroid rats. Despite the increase in T4 in euthyroid rats administered excess iodine, T3 decreased whereas in hypothyroid rats, both of them were increased. NIS, and D1 deiodinase genes expression in euthyroid rats administered excess iodine were decreased but TPO was non-significantly increased. Conclusion: Hypothyroidism increased gene expression of NIS, TPO, and induces an oxidative stress. High iodine intake decreased NIS and D1 deiodinase gene expression in euthyroid and hypothyroid rats. Moreover, excess iodine increase thyroid hormones, lipid peroxides and antioxidants in cases of euthyroid and hypothyroid rats. Therefore, screening of thyroid function and assessment of prooxidant/antioxidant status in subjects treated with drugs containing iodine and after investigations with contrast media are recommended. | ||||
| Keywords | ||||
| excess iodine; thyroid hormones; Oxidative Stress; euthyroid; hypothyroid | ||||
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