Hyaluronic Acid Complexes of Human Synovial Fluid

1. By taking advantage of the low metabolic rate of the alligator, it was possible to study the effect of insulin on the rate at which each of a large group of amino acids was utilized in vivo. 2. 'Amino acid tolerances' of both isomers of amino acids were determined in the alligator and in the rat by the injection of 10 m-moles/kg. followed by analyses of plasma amino acids at frequent intervals. The rat metabolized amino acids from 50 to 100 times as fast as the alligator. In general, the non-essential amino acids were utilized much more rapidly than the essential ones by both species. 3. Each amino acid had its characteristic tolerance curve. 4. In the alligator, insulin increased the rate of metabolism of most of the exogenous amino acids of both isomers. 5. Insulin appears to enhance the metabolism of compounds which differ greatly in chemical structure.