A COMPARISON OF THE EFFECT OF DIETARY FAT AND CARBOHYDRATE ON FREE AMINO ACIDS IN THEBLOOD PLASMA OF CHICKS

As previously reported, an increased concentration of plasma free amino acids, particularly lysine and threonine, was found when chicks were fasted for 24 hours. This increase was suppressed where a nonprotein diet was fed. Dextrose as the chief energy source in the nonprotein diet was more effective than shortening or lard in this respect. However, the degree to which the two energy sources differed was less where birds were adapted to the utilization of fat by feeding a diet rich in fat for a considerable time before making the comparison. Insulin administration to fasted chicks was found to lower plasma amino acid levels. The possible influence of interrelationships among dextrose, fat, and insulin on plasma amino acid levels is discussed.