Effect of Dietary Protein Levels on the Plasma Amino Acid Ratio and Hydroxyproline Excretion in Urine of Rats

Abstract

The relationship between the plasma amino acid ratio recommended by Whitehead and the weight gain or protein level in the diet was studied using male rats weighing about 90g. The animals were given diets containing graded amounts of casein for 9-41 days. The amino acid ratio, estimated by a modification of Whitehead's method, was found to be closely correlated with the weight gain and also the dietary protein level.When the animals were given either a rice or wheat flour diet supplemented with lysine and threonine, a close relationship between the amino acid ratio and weight gain was also observed.In our animal experiments, the hydroxyproline index which could be related to the incidence of the clinical signs of Kwashiorkor was also found to correlate well with the amino acid ratio and weight gain.