Changes in Prooxidant/Antioxidant Status
of Hyperthyroid Rats Treated with Selenium
Adela Elena Joantã1, Simona Valeria Clichici1, Gabriela Adriana Filip1, and Sanda Andrei2
1 Department of Physiology, Iuliu Hatieganu University of Medicine and Pharmacy, Cluj-Napoca, Romania
2 Department of Biochemistry, University of Agricultural Sciences and Veterinary Medicine, Cluj-Napoca, Romania
Corresponding author: Dr. Adela Elena Joantã
Department of Physiology
Iuliu Hatieganu University of Medicine and Pharmacy
Str. Emil Isac nr. 13
400023 Cluj-Napoca, Romania
Telephone: 0040 745 512428
Fax number: 0040 264 597257
E-mail: adelaelena@yahoo.com
CEJOEM 2005, Vol.11. No.2.: 123–129
Key words:
Selenium, oxidative stress, thyroid hormones, liver, myocardium
Abstract:
Natural sources of the well-known antioxidant selenium are wheat seeds, onion, tomato, garlic, cabbage, broccoli,
fish, internal organs, eggs, etc. Recent studies have shown the relationship between oxidative stress and thyroid
disorders. This study deals with the effects of reactive oxygen species and selenium administration in experimental
hyperthyroidism. The experiments were carried out in male Wistar rats divided in three groups: Group I – control,
Group II – thyroxin-treated, and Group III – thyroxin- and selenium-treated rats. Oxidative stress markers (lipid
peroxides, carbonyl level of proteins) and selenium glutathione peroxidase activity were determined in some target
tissues of thyroid hormones: liver, thyroid gland, and myocardium. Lipid peroxides were assessed using thiobarbituric
acid (TBA) method, carbonyl proteins with dinitrophenylhidrazine and selenium glutathione peroxidase activity by
spectrometry. Lipid peroxides and carbonyl level of proteins were found increased in rats treated with thyroxin
and decreased in rats treated with selenium too. Selenium glutathione peroxidase activity was increased in rats
that had been given selenium. Our results corroborate the occurrence of oxidative stress due to thyroid hormone
excess. Selenium administration led to a decrease of oxidative stress markers in target tissues and to an increase
in the level of antioxidants. Therefore, combining selenium with the classic treatment of hyperthyroidism may be recommended.
Received: 27 December 2004
Accepted: 13 June 2005
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