title: Bolus ingestion of individual branched-chain amino acids alters plasma amino acid profiles in young healthy men.
abstract: Physiological conditions in humans affect plasma amino acid profiles that might have potential for medical use. Because the branched-chain amino acids (BCAAs) leucine, isoleucine and valine are used as medicines and supplements, we investigated the acute effects of individual BCAAs (10-90 mg/kg body weight) or mixed BCAAs ingested as a bolus on plasma amino acid profiles in young healthy men. Plasma leucine levels rapidly increased and peaked around 30 min after leucine ingestion. Concentrations of plasma isoleucine, valine and phenylalanine subsequently decreased after ingestion, and those of methionine and tyrosine tended to decrease. The effects of ingested leucine on other plasma amino acids were biphasic, being higher at lower doses (10-20 mg/kg body weight). Isoleucine or valine intake also caused corresponding plasma amino acid concentrations to rapidly elevate, and peaks at 30-40 min after ingestion were much higher than that of plasma leucine after leucine ingestion. However, the increase in plasma isoleucine and valine concentrations essentially did not affect those of other plasma amino acids. The rate of decline among peak plasma BCAA concentrations was the highest for leucine, followed by isoleucine and valine. Oral mixed BCAAs promoted the decline in plasma isoleucine and valine concentrations. These results suggest that plasma leucine is a regulator of the plasma concentrations of BCAAs, methionine and aromatic amino acids.
authors: Department of General Medicine/Family and Community Medicine, Nagoya University Graduate School of Medicine, Nagoya, 466-8560 Japan.
authors: Takuya
authors: T
authors: Matsumoto
authors: Laboratory of Nutritional Biochemistry, Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, 464-8601 Japan.
authors: Koichi
authors: K
authors: Nakamura
authors: Institute for Innovation, Ajinomoto Co., Inc., Kawasaki, 210-8681 Japan.
authors: Hideki
authors: H
authors: Matsumoto
authors: Institute for Innovation, Ajinomoto Co., Inc., Kawasaki, 210-8681 Japan.
authors: Ryosei
authors: R
authors: Sakai
authors: Institute for Innovation, Ajinomoto Co., Inc., Kawasaki, 210-8681 Japan.
authors: Tomomi
authors: T
authors: Kuwahara
authors: Laboratory of Nutritional Biochemistry, Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, 464-8601 Japan.
authors: Yoshihiro
authors: Y
authors: Kadota
authors: Laboratory of Nutritional Biochemistry, Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, 464-8601 Japan.
authors: Yasuyuki
authors: Y
authors: Kitaura
authors: Department of General Medicine/Family and Community Medicine, Nagoya University Graduate School of Medicine, Nagoya, 466-8560 Japan.
authors: Juichi
authors: J
authors: Sato
authors: Laboratory of Nutritional Biochemistry, Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, 464-8601 Japan.
authors: Yoshiharu
authors: Y
authors: Shimomura
keywords: Area under curve; Branched-chain amino acids; Maximum concentration; Mood states; Oral ingestion; Plasma amino acids profile