Affiliation:
1. 1 Szent István University Department of Physiology and Biochemistry, Faculty of Veterinary Science István u. 2 H-1078 Budapest Hungary
2. 2 Alexandria University Department of Anatomy, Faculty of Veterinary Medicine Damnhur Branch Egypt
3. 3 Catholic University of Leuven Laboratory for Farm Animals Heverlee Belgium
Abstract
Energy restriction induces changes in thyroid hormone economy in the form of a complex adaptation mechanism, in order to conserve energy storage and protein reserves. In the present work, thyroid hormone serum concentrations, hepatic deiodinase enzyme activities and hepatic deiodinase mRNA expression were examined after feed restriction and fasting. We demonstrate that during energy restriction, T
3
concentration is lowered due to a decreased T
4
activation and increased T
3
inactivation. We show that hepatic type-I deiodinase (D1) is not affected by energy restriction, however, hepatic D2 is decreased on both transcriptional and enzyme activity levels. Furthermore, hepatic D3 is increased after feed restriction in the liver. We also show that the hypothalamic feedback is not involved in the changes in serum T
3
and T
4
concentrations. Our data indicate that D2 enzyme contributes to the special hormone-exporting role of the chicken liver and this enzyme can be modulated by feed restriction.
Cited by
7 articles.
订阅此论文施引文献
订阅此论文施引文献，注册后可以免费订阅5篇论文的施引文献，订阅后可以查看论文全部施引文献