Cadmium induced thyroid dysfunction in chicken: hepatic type I iodothyronine 5'-monodeiodinase activity and role of lipid peroxidation.
Administration of cadmium chloride (2.5 mg/kg body weight/day) to chickens daily for 15 days decreased serum triiodothyronine (T3) concentration (by 68.75%) without altering the levels of serum thyroxine (T4). Hepatic 5'-monodeiodinase (5'D-I) and superoxide dismutase (SOD) activities were also decreased (by 90.47% and 20.81% respectively) with a concomitant increase in lipid peroxidation (LPO, by 206.25%). Administration of the antioxidant vitamin E (alpha-tocopherol, 5 mg/kg body weight on alternate days) to cadmium intoxicated chickens restored thyroid function by maintaining normal hepatic 5'D-I activity and serum thyroid hormone concentrations. It also prevented cadmium-induced increase in LPO. We conclude that the metal-induced inhibition in hepatic 5'D-I activity is mediated through LPO.
Gupta
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Thyroid Research Unit, School of Life Sciences, D.A. University, Vigyan Bhawan, Indore, India.
Kar
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D000818:Animals; D019256:Cadmium Chloride / Q000633:toxicity*; D002645:Chickens; D007453:Iodide Peroxidase / Q000378:metabolism*; D015227:Lipid Peroxidation / Q000187:drug effects; D008099:Liver / Q000201:enzymology*; D013482:Superoxide Dismutase / Q000378:metabolism; D013959:Thyroid Diseases / Q000097:blood / Q000139:chemically induced*; D013961:Thyroid Gland / Q000187:drug effects* / Q000378:metabolism; D013974:Thyroxine / Q000097:blood; D014284:Triiodothyronine / Q000097:blood; D014810:Vitamin E / Q000494:pharmacology
D014284:Triiodothyronine; D014810:Vitamin E; D007453:Iodide Peroxidase; D013482:Superoxide Dismutase; D019256:Cadmium Chloride; D013974:Thyroxine