Possible Interaction: Threonine and Tryptophan

“Generally, Trp addition linearly increased gain and feed intake at a Thr :Lys ratio of 0.60 and 0.65 but not at a Thr:Lys ratio of 0.55.”

“High level of L-threonine , L-alpha-alanine, L-valine (100 mM) considerably inhibit the accumulation of L-tryptophan from 0.24 or 2.40 mM solution, the highest inhibition (78-96%) being related to the sodium-dependent transport mechanism.”

“Since supplementation with threonine prevents the accumulation of fat in the livers … per cent casein basal diet (1, 3), and since the inclusion of tryptophan … threonine under certain conditions (5), an attempt has also been made to determine … the effects of these two amino acids and that of methionine.”

“The internal tryptophan concentration increases during the period of indole excretion, suggesting that threonine acts by increasing the activity of the tryptophan pathway.”