previous studies with livers from fed rats perfused in the single-pass mode have shown that regulatory amino acids ( leu , tyr , gln , pro , met , his , and trp ) as a group as well as leucine alone inhibit deprivation-induced protein degradation optimally at 0.5 and 4 times ( x ) normal plasma amino acid concentrations .
C0017797
gln
C0002520
amino acid