Abstract
Supplementing the casein diet with 0.8% nitrogen content with 0.2% each of L-lysine and DL-threonine or 0.2% DL-threonine alone showed some effects in body weight and the xanthine oxidase activity of liver of rats but did not show much effect. The effect of the same amount of L-lysine and DL-threonine to the same casein diet which has been supplemented with 0.2% DL-methionine was not also observed.
From the above observations it was considered that the effect of supplementing 0.2% each of L-lysine and DL-threonine to the dried mixed diet of 0.8% nitrogen content which was previously must be the complementary effect of these amino acids rather than the specific effect known for threonine in the case of the casein diet of low protein level.
On the other hand, significant increases in body weight of rats were observed when supplemented with 0.2% each of L-lysine and DL-threonine in addition to 0.2% each of DL-methionine and DL-tryptophan to the casein diet. The rats on the casein diet did not show fatty liver but those given the same diet supplemented with 0.2% DL-methionine.
