Effect of Time Factor on the Nitrogen Sparing effect of Dietary Carbohydrate

The effect sf the time factor on the nitrogen sparing effect of dietary carbohydrate
was studied in growing rats. During a 18.day feeding perid ns significant
differences were observed in weight gains of rats receiving carbohydrate with
the dietary protein (casein) or 8 h after protein was fed. Rats recenving carbohydrate
with the protein retained significantly more nitrogen during the first day
sf the experiment than those receiving protein and carbohydrate separately,
but this difference was not evident after the first day.
Rats receiving casein alone had elevated plasma amino acid levels, which
remained high until carbohydrate was fed 8 h later. The pattern sf fall of the
amino acids bore a resemblance to the pattern of amino acids in carcass protein.
Rats fasted for 16 h had low levels of liver glycogen; when protein was given
alone, some was utilized for glycogen formation. Carbohydrate, given 8 h after
the protein, increased liver glycogen to normal levels and spared the protein
fed at the next meal.