Responses of plasma glutamine, free tryptophan and branched-chain amino acids to prolonged exercise after a regime designed to reduce muscle glycogen

1997 ◽  
Vol 75 (6) ◽  
pp. 543-548 ◽  
Author(s):  
Cathy L. Zanker ◽  
Ian L. Swaine ◽  
Linda M. Castell ◽  
Eric A. Newsholme
Keyword(s):  
Amino Acids ◽  
Muscle Glycogen ◽  
Prolonged Exercise ◽  
Branched Chain Amino Acids ◽  
Free Tryptophan ◽  
Branched Chain

Carbohydrates, Branched-Chain Amino Acids, and Endurances: The Central Fatigue Hypothesis

1995 ◽  
Vol 5 (s1) ◽  
pp. S29-S38 ◽  
Author(s):  
J. Mark Davis
Keyword(s):  
Amino Acids ◽  
Exercise Performance ◽  
Prolonged Exercise ◽  
Central Fatigue ◽  
Branched Chain Amino Acids ◽  
Convincing Evidence ◽  
Free Tryptophan ◽  
Branched Chain ◽  
Sport And Exercise ◽  
Exercise Induced

The mechanisms of central fatigue are largely unexplored, but the central fatigue hypothesis suggests that increased brain serotonin (5-HT) can cause a deterioration in sport and exercise performance. There is now convincing evidence that exercise-induced increases in the plasma free tryptophan (f-TRP)/branched-chain amino acids (BCCA) ratio are associated with increased brain 5-HT and the onset of fatigue during prolonged exercise. Furthermore, when drugs are administered to alter brain 5-HT, they have the predicted effects on exercise performance. The influence of nutritional manipulations of f-TRP/BCCA on performance is less well established. The effects of BCCA supplementation on exercise performance are mixed, and the published studies often suffer from methodological flaws. Alternatively, dramatic reductions in f-TRP/BCCA and enhanced performance accompany carbohydrate feedings during prolonged exercise. However, it is difficult to distinguish between the effects of carbohydrate feedings on mechanisms that reside in the brain versus the muscles themselves.

scholarly journals Mechanisms of the Pellagragenic Effect of Leucine: Stimulation of Hepatic Tryptophan Oxidation by Administration of Branched-Chain Amino Acids to Healthy Human Volunteers and the Role of Plasma Free Tryptophan and Total Kynurenines

2014 ◽  
Vol 7 ◽  
pp. IJTR.S18231 ◽  
Author(s):  
Abdulla A-B Badawy ◽  
Sarah L. Lake ◽  
Donald M. Dougherty
Keyword(s):  
Amino Acids ◽  
Hepatic Uptake ◽  
Branched Chain Amino Acids ◽  
Amino Acid Mixture ◽  
Kynurenine Pathway ◽  
Acid Mixture ◽  
Healthy Human ◽  
Free Tryptophan ◽  
Tryptophan Oxidation ◽  
Branched Chain

The pellagragenic effect of leucine (Leu) has been proposed to involve modulation of L-tryptophan (Trp) metabolism along the hepatic kynurenine pathway. Here, we discuss some of the mechanisms suggested and report the effects in healthy volunteers of single doses of Leu (4.05–6.75 g) administered in a 16-amino acid mixture on concentrations of plasma Trp and its kynurenine metabolites. Flux of Trp through Trp 2,3-dioxygenase (TDO) is dose-dependently enhanced most probably by Leu and can be attributed to TDO activation. Trp oxidation is better expressed using plasma total kynurenines, rather than kynurenine, and free, rather than total, Trp. Increased hepatic Trp oxidation may be an additional mechanism of action of branched-chain amino acids in the acute Trp depletion test. Inhibition of intestinal absorption or hepatic uptake of Trp by Leu can be excluded. Potential mechanisms of the aggravation of pellagra symptoms by Leu are discussed.

Anorexia and Plasma Levels of Free Tryptophan, Branched Chain Amino Acids, and Ghrelin in Hemodialysis Patients

2009 ◽  
Vol 19 (3) ◽  
pp. 248-255 ◽  
Author(s):  
Maurizio Bossola ◽  
Donata Scribano ◽  
Luigi Colacicco ◽  
Barbara Tavazzi ◽  
Stefania Giungi ◽  
...  
Keyword(s):  
Amino Acids ◽  
Plasma Levels ◽  
Branched Chain Amino Acids ◽  
Hemodialysis Patients ◽  
Free Tryptophan ◽  
Branched Chain

scholarly journals Effects of glucose, glucose plus branched-chain amino acids, or placebo on bike performance over 100 km

1996 ◽  
Vol 81 (6) ◽  
pp. 2644-2650 ◽  
Author(s):  
Klavs Madsen ◽  
Dave A. Maclean ◽  
Bente Kiens ◽  
Dirk Christensen
Keyword(s):  
Amino Acids ◽  
Oxygen Uptake ◽  
Prolonged Exercise ◽  
Respiratory Exchange Ratio ◽  
Branched Chain Amino Acids ◽  
Plasma Ammonia ◽  
Exercise Period ◽  
Placebo Trial ◽  
Branched Chain ◽  
Performance Times

Madsen, Klavs, Dave A. MacLean, Bente Kiens, and Dirk Christensen. Effects of glucose, glucose plus branched-chain amino acids, or placebo on bike performance over 100 km. J. Appl. Physiol. 81(6): 2644–2650, 1996.—This study was undertaken to determine the effects of ingesting either glucose ( trial G) or glucose plus branched-chain amino acids (BCAA; trial B), compared with placebo ( trial P), during prolonged exercise. Nine well-trained cyclists with a maximal oxygen uptake of 63.1 ± 1.5 ml O2 ⋅ min−1 ⋅ kg−1performed three laboratory trials consisting of 100 km of cycling separated by 7 days between each trial. During these trials, the subjects were encouraged to complete the 100 km as fast as possible on their own bicycles connected to a magnetic brake. No differences in performance times were observed between the three trials (160.1 ± 4.1, 157.2 ± 4.5, and 159.8 ± 3.7 min, respectively). In trial B, plasma BCAA levels increased from 339 ± 28 μM at rest to 1,026 ± 62 μM after exercise ( P < 0.01). Plasma ammonia concentrations increased during the entire exercise period for all three trials and were significantly higher in trial B compared with trials G and P ( P< 0.05). The respiratory exchange ratio was similar in the three trials during the first 90 min of exercise; thereafter, it tended to drop more in trial P than in trials G and B. These data suggest that neither glucose nor glucose plus BCAA ingestion during 100 km of cycling enhance performance in well-trained cyclists.

Supplementation with Branched-Chain Amino Acids (BCAA) and Tryptophan has no Effect on Performance during Prolonged Exercise

1994 ◽  
Vol 87 (s1) ◽  
pp. 52-52
Author(s):  
G van Hall ◽  
JSH Raaymakers ◽  
WHM Saris ◽  
AJM Wagenmakers
Keyword(s):  
Amino Acids ◽  
Prolonged Exercise ◽  
Branched Chain Amino Acids ◽  
Branched Chain

Effect of chronic supplementation with branched-chain amino acids on the performance and hepatic and muscle glycogen content in trained rats

Life Sciences ◽  
2006 ◽  
Vol 79 (14) ◽  
pp. 1343-1348 ◽  
Author(s):  
Jonas A. de Araujo ◽  
Gina Falavigna ◽  
Marcelo M. Rogero ◽  
Ivanir S.O. Pires ◽  
Rogerio G. Pedrosa ◽  
...  
Keyword(s):  
Amino Acids ◽  
Muscle Glycogen ◽  
Glycogen Content ◽  
Branched Chain Amino Acids ◽  
Muscle Glycogen Content ◽  
Branched Chain

Plasma amino acid and ammonia responses to altered dietary intakes prior to prolonged exercise in humans

1992 ◽  
Vol 70 (4) ◽  
pp. 420-427 ◽  
Author(s):  
D. A. MacLean ◽  
L. L. Spriet ◽  
T. E. Graham
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Prolonged Exercise ◽  
Plasma Concentrations ◽  
Latin Square ◽  
Branched Chain Amino Acids ◽  
Dietary Intakes ◽  
Rate Of Increase ◽  
Branched Chain ◽  
Exercise In Humans

This study examined the effects of altered dietary intakes on amino acid and ammonia (NH3) responses prior to and during prolonged exercise in humans. Six male recreational cyclists rode to exhaustion at 75% of [Formula: see text] following 3 days on a low carbohydrate (LC), mixed (M), or high carbohydrate (HC) diet in a latin square design. There were differences (p < 0.05) in exercise times among all treatments (58.8 ± 3.7, 112.1 ± 7.3, and 152.9 ± 10.3 min for the LC, M, and HC treatments, respectively). The rate of increase in plasma NH3 during exercise was greater (p < 0.05) during the LC trial. The LC trial was also characterized by higher (p < 0.05) resting plasma concentrations of branched chain amino acids (BCAA) and a greater decrease in these amino acids during exercise (p < 0.05), as compared with the other two treatments. Both plasma BCAA and NH3 were susceptible to dietary manipulations. These findings suggest that limited carbohydrate availability in association with increased BCAA availability results in enhanced BCAA metabolism during exercise. This is reflected in a greater rate of increase in plasma NH3 and is consistent with the hypothesis that a significant fraction of the NH3 released during a prolonged, submaximal exercise bout is from amino acid catabolism.Key words: AMP deaminase, branched chain amino acids, branched chain keto acid dehydrogenase, glycogen, purine nucleotide cycle.

Effects of carbohydrate feedings on plasma free tryptophan and branched-chain amino acids during prolonged cycling

1992 ◽  
Vol 65 (6) ◽  
pp. 513-519 ◽  
Author(s):  
J. Mark Davis ◽  
Stephen P. Bailey ◽  
Jeffrey A. Woods ◽  
Floyd J. Galiano ◽  
Marc T. Hamilton ◽  
...  
Keyword(s):  
Amino Acids ◽  
Branched Chain Amino Acids ◽  
Free Tryptophan ◽  
Branched Chain
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