Abstract
The ability of rat liver homogenate for decomposing threonine in vitro was increased when the protein level of the diet had been increased. It was also increased by the addition of threonine or lysine to twenty percent casein diet, though the degree of increase in the former was higher than the latter. Since the addition of the amino acid had been ceased, elevated ability was kept for considerable length of time in the case of threonine. But, in the case of lysine the ability was decreased in a week to the level of before the addition. The addition of other amino acids, such as methionine, leucine or glutamic acid had no influence on the ability
