Inverse relationship between protein intake and plasma free amino acids in healthy men at physical exercise.
Am J Physiol Endocrinol Metab
; 278(5): E857-67, 2000 May.
Article
in En
| MEDLINE
| ID: mdl-10780942
ABSTRACT
The effect of a "normal" (n = 8) and "high" (n = 6) protein intake (1 and 2.5 g x kg(-1) x day(-1), respectively) and of exercise on plasma amino acid (AA) concentrations, insulin, and glucagon concentrations was followed throughout a continuous 24-h period in adult male subjects at energy balance after six days on a standardized diet and exercise program. Subjects were fasting from 2100 on day 6 to 1200 on day 7 and then fed 10 identical meals hourly until 2100. Physical exercise was performed (46% maximal oxygen uptake) between 0830 and 1000 (fasting) and in a fed state (1600-1730) on each day. The normal-protein group showed fasting plasma AA concentrations that were higher (P < 0.05) than those for the high-protein group, except for leucine, methionine, and tyrosine. Glutamine, glycine, alanine, taurine, and threonine concentrations were distinctly higher ( approximately 30% or greater) throughout the 24-h period in subjects consuming the normal- vs. the high-protein diets. Exercise appeared to increase, although not profoundly, the plasma concentrations of amino acids except for glutamate, histidine, ornithine, and tryptophan. The profound diet-related differences in plasma AA concentrations are only partially explained by differences in the renal clearance of the amino acids. We speculate on the possible metabolic basis for these findings.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Dietary Proteins
/
Exercise
/
Amino Acids
Limits:
Adult
/
Humans
/
Male
Language:
En
Journal:
Am J Physiol Endocrinol Metab
Journal subject:
ENDOCRINOLOGIA
/
FISIOLOGIA
/
METABOLISMO
Year:
2000
Document type:
Article
Affiliation country: