Amino acid arterial concentration and muscle exchange during submaximal arm and leg exercise: the effect of dihydroxyacetone and pyruvate.
The mixture of dihydroxyacetone and pyruvate (DHAP) is an ergogenic aid that enhances muscle glucose extraction during prolonged aerobic exercise. In order to evaluate the effect of DHAP on muscle amino acid extraction during exercise, we measured arterial concentration and muscle exchange of amino acids in 18 untrained healthy male subjects (aged 20-30 years) performing dynamic arm (60% VO2 max, n = 9) or leg (70% VO2 max, n = 9) exercise to exhaustion with and without dietary supplementation of DHAP. The subjects consumed diets (146 kJ kg body weight-1 day-1) containing either 100 g polyglucose, Polycose (placebo, P) or DHAP (3:1, treatment) substituted for a portion of carbohydrate. The two diets were administered in a double-blind, random, crossover order for a 7-day period. At least 7 days separated the dietary protocols. Blood samples were drawn through radial artery and axillary or femoral vein catheters at rest, during exercise and at exhaustion. Arterial alanine concentration increased by 30% during arm exercise and by 50-60% during leg exercise. No other arterial amino acid concentration changed during exercise. At exhaustion, arterial alanine concentration decreased to pre-exercise levels with arm exercise but remained elevated after leg exercise. Despite changes in arterial concentrations of alanine with exercise, muscle exchange of alanine was not altered with exercise. Exercise did not alter muscle exchange of any amino acid. Arterial amino acid concentrations and muscle exchange of amino acids with exercise were similar with or without DHAP feeding.(ABSTRACT TRUNCATED AT 250 WORDS)
Stanko
R T
RT
Department of Medicine, Montefiore University Hospital, Pittsburgh, Pennsylvania 15213.
Diven
W F
WF
Robertson
R J
RJ
Spina
R J
RJ
Galbreath
R W
RW
Reilly
J J
JJ
Goss
F L
FL
D000328:Adult; D000409:Alanine / Q000097:blood / Q000378:metabolism; D000596:Amino Acids / Q000097:blood / Q000378:metabolism*; D000704:Analysis of Variance; D001132:Arm / Q000502:physiology; D004040:Dietary Carbohydrates / Q000378:metabolism; D004098:Dihydroxyacetone / Q000494:pharmacology*; D004311:Double-Blind Method; D004734:Energy Metabolism / Q000187:drug effects; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D006801:Humans; D007866:Leg / Q000502:physiology; D008297:Male; D009124:Muscle Proteins / Q000378:metabolism; D009132:Muscles / Q000378:metabolism*; D010807:Physical Endurance / Q000187:drug effects; D011773:Pyruvates / Q000494:pharmacology*
D000596:Amino Acids; D004040:Dietary Carbohydrates; D009124:Muscle Proteins; D011773:Pyruvates; D004098:Dihydroxyacetone; D000409:Alanine