The change in the venous concentration of amino acids in normal male and female adults was studied. After the brief fast (about 40 hours) except for a higher concentration of branched-chain amino acids in the plasma of female subjects, there was essentially no significant difference between the plasma composition of amino acids in female or male subjects. In only one male subject (Rohler's Index was 106), the transient fall of the branched-chain amino acid concentrations.
Low caloric diet feedings resulted in a marked reductions of the plasma serine, glutamic acid, proline, glycine, arginine and threonine. On the other hand, high protein and high fat diet feedings resulted is a remarkable increasing of the branched-chain amino acid concentration and marked reduction of the plasma alanine concentration.