Partial Food Restriction Increases Hepatic Inner Ring Deiodinating Activity in the Chicken and the Rat

• Published in: General and comparative endocrinology Vol. 100; no. 3; pp. 334 - 338
• Main Authors: Darras, V.M., Cokelaere, M., Dewil, E., Arnouts, S., Decuypere, E., Kühn, E.R.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.12.1995
• Subjects: Animals; biological differences; blood plasma; Body Weight; Chickens; Diet - adverse effects; diferencias biologicas; difference biologique; Female; foie; higado; inanicion; inanition; iode; iodine; liver; Liver - metabolism; Male; plasma sanguin; plasma sanguineo; pollo; poulet; rat; rata; Rats; Rats, Wistar; starvation; Thyroid Hormones - blood; thyroxine; tiroxina; triiodothyronine; triyodotironina; yodo
• ISSN: 0016-6480; 1095-6840
• DOI: 10.1006/gcen.1995.1164

The effects of a long term partial food restriction were studied in chickens and rats. In chickens the treatment resulted in increased plasma T 4 levels while T 4 levels in rates remained unchanged. Plasma T 4 decreased in both species. In vitro hepatic outer ring deiodinating type I (ORD-I) activity was not influenced by the food restriction, suggesting that the amount of ORD-I enzyme present in the liver remained unchanged. In vitro hepatic inner ring deiodinating type III activity, on the contrary, was greatly increased in both species. This increase may contribute to the decreased circulating T 3 levels by increasing the degradation of T 3 and diverting the deiodination of T 4 to rT 3 instead of to T 3.