Disturbances in Thyroid Hormone Metabolism in Rats Exposed to γ- Radiation and Carbon Tetrachloride: The Role of N- acetyl cysteine and Sodium Selenite

Document Type : Original Article

Author

Department of Radiation Biology Research, National Center for Radiation Research and Technology, Atomic Energy Authority (EAEA), PO box 29, Nasr City, Cairo, Egypt

Abstract

THIS work aims at detecting the disturbances in thyroid hormone metabolism in male rats exposed to liver injury by γ- radiation and/or carbon tetrachloride (CCl4), in addition to investigating the modulatory role of N-acetyl cysteine (NAC) and sodium selenite (Se) supplementation. Subcutaneous injection of CCl4 twice a week for 8 weeks and/or whole-body irradiation (6 Gy, single dose) one day after the last dose of CCl4 induced hepatotoxicity as manifested by elevation of serum alanine aminotransferase and gamma-glutamyl transferase and oxidative stress in liver tissue. Moreover, significant increases were recorded in pro-inflammatory markers: nuclear factor kappa B and interleukin- 1beta levels. This was also accompanied by a significant decrease in the activity of type 1 iodothyronine deiodinase in the hepatic tissue and triiodothyronine and thyroxin levels in serum, while thyroid-stimulating hormone showed a non-significant increase. Histological examination of liver sections showed marked alterations. However, oral supplementation of NAC and Se for 2 weeks after exposure to CCl4 and/or γ- radiation attenuated the changes induced by these toxins. In conclusion, supplementation of NAC & Se may be useful to attenuate thyroid hormone metabolic disturbances associated with liver injury induced by chemical and physical environmental toxins.

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