Effects of triiodothyronine administration on dietary [14C]triolein partitioning between deposition in adipose tissue and oxidation to [14C]CO2 in ad libitum-fed or food-restricted rats

Effects of Triiodothyronine Administration on the Disposal of Oral [1-14C]-Triolein, Lipoprotein Lipase Activity and Lipogenesis in the Rat during Lactation and on Removal of the Litter

“…Hyperthyroidism has been associated with an increase in rat heart LPL activity [19,21,22], whereas in the skeletal muscle the enzyme activity is decreased [22]. In the present study there were no changes in the heart or soleus LPL activity 24 h after T3 administration in the lactating or litter-removed rats (Table 3).…”

“…The addition of T3 to cultured adipocytes of normal male rats decreases LPL activity, and the synthesis of the enzyme [17]. Similarly, administration of T3 depresses the raised activity of LPL in adipose tissue of food-restricted rats [19]. Dietary [14C]lipid accumulation in the skin changed in parallel with the adipose tissue in all the groups studied ( Table 2).…”

“…The other major source of milk lipid is synthesis de novo (lipogenesis) within the gland from glucose (see [16]). Studies with non-pregnant non-lactating rats have shown that excess thyroid hormones inhibit LPL activity in adipose tissue [17][18][19], and have variable effects on activity in heart and skeletal muscle [20][21][22]. In contrast, hyperthyroidism increases hepatic lipogenesis [23][24][25] …”

Effects of tri-iodothyronine administration on the disposal of oral [1-14C]triolein, lipoprotein lipase activity and lipogenesis in the rat during lactation and on removal of the litter

“…The addition of T3 to cultured adipocytes of normal male rats decreases LPL activity, and the synthesis of the enzyme [17]. Similarly, administration of T3 depresses the raised activity of LPL in adipose tissue of food-restricted rats [19].…”

“…The other major source of milk lipid is synthesis de novo (lipogenesis) within the gland from glucose (see [16]). Studies with non-pregnant non-lactating rats have shown that excess thyroid hormones inhibit LPL activity in adipose tissue [17][18][19], and have variable effects on activity in heart and skeletal muscle [20][21][22]. In contrast, hyperthyroidism increases hepatic lipogenesis [23][24][25].…”