Table 1

Plasma concentrations of phenylalanine and tyrosine before and 6 hours after ingesting the AA mixture

Amino acidMorning baseline; mean (and SD) μmol/LPostmixture; mean (and SD) μmol/L
Phenylalanine balanced47.7 (4.6)65.9 (23.8)†
Phenylalanine APTD49.6 (9.2)12.7 (5.8)‡
Phenylalanine APTD + l-DOPA46.2 (5.5)11.7 (4.7)‡
Tyrosine balanced52.9 (7.3)154.8 (87.7)‡
Tyrosine APTD54.3 (9.2)10.8 (3.2)*
Tyrosine APTD + l-DOPA52.1 (8.1)8.8 (2.7)*

  • AA = amino acid; APTD = acute phenylalanine/tyrosine depletion; l-DOPA = l-dihydroxyphenylalanine; SD = standard deviation.

  • Planned comparisons:

  • ↵* p < 0.05

  • ↵† p < 0.01

  • ↵‡ p < 0.001