Table 2.

Concentration of amino acids in plasma during consumption of basal diet and basal diet with added leucine.

Amino Acid	Basal diet (μmol/L)	Basal diet + leucine (μmol/L)
Alanine	780 ± 68	645 ± 20
Glutamic Acid	74 ± 12	78 ± 6
Asparagine	134 ± 11	107 ± 7**
Serine	186 ± 25	134 ± 9
Glutamine	1096 ± 192	959 ± 141
Histidine	132 ± 8	114 ± 6**
Glycine	303 ± 73	238 ± 23
Threonine	227 ± 26	189 ± 27**
Arginine	137 ± 6	129 ± 9
Aspartic Acid	14.4 ± 4.4	9.6 ± 1.2
Phenylalanine	121 ± 12	113 ± 6
Tyrosine	192 ± 17	151 ± 14*
Valine	508 ± 47	391 ± 24*
Methionine	117 ± 21	102 ± 14
Tryptophan	123 ± 6	122 ± 6
Isoleucine	151 ± 17	116 ± 10*
Leucine	338 ± 36	738 ± 66***
Lysine	362 ± 39	321 ± 38

Amino acid concentrations in plasma were determined by HPLC as described in Methods. The differences between the period of consumption of the basal diet and during consumption of the basal diet with added leucine are significant at *P < .05, **P < .01, and ***P < .001.