Opposite effects of zinc and melatonin on thyroid hormones in rats.
Toxicology
; 195(1): 69-75, 2004 Jan 15.
Article
em En
| MEDLINE
| ID: mdl-14698569
ABSTRACT
The present study was conducted to investigate how thyroid function in rats is affected by administration of 3 mg per kg per day of zinc and/or melatonin. The study was conducted with 40 Sprague-Dawley adult male rats equally divided into four groups 1 (controls), 2 (zinc-only), 3 (melatonin-only) and 4 (zinc- and melatonin-supplemented). The supplementation was continued for 4 weeks after which the animals were sacrificed and plasma samples were obtained for determination of zinc, melatonin, free- and total triiodothyronine (T3), thyroxine (T4) and thyroid-stimulating hormone (TSH) levels. The free T3, T4 and TSH levels were lower in the melatonin group than in all other groups (P<0.01), while free- and total T3 levels were higher in the zinc group (P<0.01). The group that received zinc and melatonin combined had free thyroid hormone levels higher than the only melatonin group. These results show that melatonin has a thyroid function suppressing action, just the opposite to the actions of zinc. When zinc is administered along with melatonin, its thyroid function suppression is diminished.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Hormônios Tireóideos
/
Zinco
/
Melatonina
Limite:
Animals
Idioma:
En
Ano de publicação:
2004
Tipo de documento:
Article