Time Cource of Tissue Free Amino acid Concentration and of the Incorporation of C¹⁴-threonine into Tissue Proteins of Rats Fed on a Diet Containing Balanced Amino acid Mixture (Part 1)

On the changes in tissue free amino acid concentration

Abstract

Rats were fed on a diet containing 15% of a balanced amino acid mixture for only one hour after 23 hours' fasting. Time cource experiment of free amino acid (FAA) in plasma showed the increase till 8-12 hours gradually and then the decrease to the original levels by 24 hours after feeding. Elevation of free threonine, lysine and alanine were great, but the levels of isoleucine, histidine and arginine were almost unchanged. FAA in liver and muscle, on the other hand, initially decreased by feeding and then returned to original level. Diurnal change of FAA content in liver was greater than in muscle.