Title of article :
Circadian Variations in Thyroid Hormone Levels of Nonpregnant Uniparous Fat-Tailed Iranian Ewes in Summer
Author/Authors :
NAZIFI, Saeed shiraz university - School of Veterinary Medicine - Department of Clinical Sciences, شيراز, ايران , SAEB, Mahdi shiraz university - School of Veterinary Medicine - Department of Basic Sciences, شيراز, ايران , HASANKHANI, Mahdi shiraz university - School of Veterinary Medicine - Department of Clinical Sciences, شيراز, ايران , ANSARI-LARI, Maryam shiraz university - School of Veterinary Medicine - Department of Food Hygiene, شيراز, ايران , GHAFARI, Narjes shiraz university - School of Veterinary Medicine - Department of Clinical Sciences, شيراز, ايران , HASANSHAHI, Fatemeh shiraz university - School of Veterinary Medicine - Department of Clinical Sciences, شيراز, ايران
Abstract :
Circadian variations in serum triiodothyronine (T3), thyroxine (T4), free triiodothyronine (fT3), and free thyroxine (fT4) levels were investigated in Iranian ewes. For that purpose, blood samples were collected from the jugular veins of 15 adult clinically healthy Iranian nonpregnant uniparous ewes every 6 h (0600, 1200, 1800, and 0000) during 6 days in summer with a mean ambient temperature of 40 °C. Serum T3, T4, fT3, and fT4 were measured by radioimmunoassay. There were statistically significant differences in thyroid hormone concentrations (T3, T4, fT3, and fT4) at different hours of the day. The results revealed that serum T3, T4, fT3, and fT4 levels were highest at 1800 (P 0.05). Significant 24 h periodicity in the serum levels of T3, T4, fT4 and fT3 was observed in nonpregnant uniparous Iranian ewes. It is concluded that circadian rhythm was observed in serum thyroid hormones.
Keywords :
Circadian rhythm , triiodothyronine , thyroxine , nonpregnant uniparous ewes
Journal title :
Turkish Journal of Veterinary and Animal Sciences
Journal title :
Turkish Journal of Veterinary and Animal Sciences
