EFFECT OF INSULIN ON FREE AMINO ACIDS IN CAIMAN TISSUE AND PLASMA

1. 1. Caimans (Caiman latirostris) were injected with insulin and the free amino acid concentrations of plasmas and tissue homogenates were compared with non-injected controls. 2. 2. Insulin decreased the concentration of all amino acids in the plasma and kidney, and of essential amino acids in the muscle, liver, heart and brain. 3. 3. Tissue non-essential amino acids generally, and glutamine, glycine and alanine particularly, were either not affected by insulin, or were actually increased in tissues other than kidney. 4. 4. It was concluded that after insulin amino acids of the cells and extra-cellular fluids are converted into protein, and that those in excess of requirements for protein synthesis are used in the synthesis of glutamine, glycine and alanine. © 1968.