Mental fatigue-induced decrease in levels of several plasma amino acids.
To investigate the relation between plasma amino acid levels and mental fatigue, we measured the plasma concentrations of 20 amino acids in 9 healthy volunteers before and after a fatigue-inducing mental task session for 8 hr. As fatigue-inducing mental tasks, the subjects performed an advanced trail making test, a Japanese KANA pick up test, and a mirror drawing test. As a control, 8-hr relaxation session was performed in the same subjects at an interval of 4 weeks. Immediately after the fatigue session, the plasma levels of branched-chain amino acids, tyrosine, cysteine, methionine, lysine, and arginine were below those after a relaxation session. The values for other blood parameters including total protein, albumin, glucose, and total cholesterol did not show any differences between the 2 sessions. These results indicate that mental fatigue may be characterized by a decrease in the plasma level of these amino acids.
Mizuno
K
K
Department of Physiology, Osaka City University Graduate School of Medicine, Osaka, Japan.
Tanaka
M
M
Nozaki
S
S
Yamaguti
K
K
Mizuma
H
H
Sasabe
T
T
Sugino
T
T
Shirai
T
T
Kataoka
Y
Y
Kajimoto
Y
Y
Kuratsune
H
H
Kajimoto
O
O
Watanabe
Y
Y
D000328:Adult; D000596:Amino Acids / Q000032:analysis / Q000097:blood*; D000597:Amino Acids, Branched-Chain / Q000032:analysis / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism; D001921:Brain / Q000378:metabolism / Q000503:physiopathology; D001923:Brain Chemistry / Q000502:physiology; D002784:Cholesterol / Q000097:blood; D015536:Down-Regulation / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D005222:Mental Fatigue / Q000097:blood* / Q000503:physiopathology*; D009483:Neuropsychological Tests; D012063:Relaxation / Q000502:physiology; D012709:Serum Albumin / Q000378:metabolism; D013997:Time Factors
D000596:Amino Acids; D000597:Amino Acids, Branched-Chain; D001786:Blood Glucose; D012709:Serum Albumin; D002784:Cholesterol