Age affects the generation of serum thyronine-binding protein by rats fed a low protein-high carbohydrate diet.
The feeding of a low protein-high carbohydrate (PM) diet to young (8-week-old) rats induces the production of serum thyronine-binding globulin. The effect of age on this process was studied in older (5-month-old) rats. In contrast to the findings in 8-week-old rats, no significant differences in the serum concentrations of T3 and free T3 and the percentage of free T3 (equilibrium dialysis) were observed between the 5-month-old rats fed the control diet and those fed the PM diet. There were also no significant differences between the two diet groups in the distribution of tracer [125I]T4 and [125I]T3 among the serum proteins as assessed by gel electrophoresis. The changes in thyronine-binding globulin and subsequent alterations in T3 binding previously observed in young rats fed a PM diet do not occur in older rats, suggesting that the age and perhaps the weight of rats must be considered in studies related to diet-induced effects on thyroid hormone economy.
D000367:Age Factors; D000818:Animals; D001835:Body Weight; D004040:Dietary Carbohydrates / Q000008:administration & dosage*; D004044:Dietary Proteins / Q000008:administration & dosage*; D051381:Rats; D011924:Rats, Zucker; D011956:Receptors, Cell Surface / Q000378:metabolism*; D011988:Receptors, Thyroid Hormone; D013974:Thyroxine / Q000097:blood; D014284:Triiodothyronine / Q000097:blood
D004040:Dietary Carbohydrates; D004044:Dietary Proteins; D011956:Receptors, Cell Surface; D011988:Receptors, Thyroid Hormone; D014284:Triiodothyronine; D013974:Thyroxine