Abstract
Changes in the metabolism in vivo of amino acids with the lapse of time after feeding a diet were investigated by measuring the incorporation of 14C into some body components one hour after injection with 14C-amino acid mixture.
The incorporation of 14C into protein in the liver and carcass was rather constant, but that into blood sugar, liver glycogen, and lipids in the liver and carcass showed a change with the lapse of time after feeding a 25% casein diet or a protein-free diet. The incorporation of 14C into liver glycogen was stimulated shortly after feeding, but it was reduced at 7hr, when a large amount of glycogen was still in the liver. On the contrary, the specific activity of blood sugar increased with the lapse of time after feeding. The conversion of 14C-amino acids into lipids in the liver and carcass was stimulated shortly after feeding.
The incorporation of 14C into protein was higher in the rats fed the protein-free diet than in those fed the 25% casein diet, and the higher incorporation was partly counterbalanced by the lower incorporation of 14C into lipids and glycogen in the rats fed the protein-free diet.
