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

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.

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

The Weight Loss Effects of Branched Chain Amino Acids and Vitamin B6: A Randomized Controlled Trial on Obese and Overweight Women

2018 ◽  
Vol 88 (1-2) ◽  
pp. 80-89 ◽  
Author(s):  
Zahra Shakibay Novin ◽  
Saeed Ghavamzadeh ◽  
Alireza Mehdizadeh
Keyword(s):  
Amino Acids ◽  
Weight Loss ◽  
Body Composition ◽  
Vitamin B6 ◽  
Controlled Trial ◽  
Density Lipoprotein ◽  
Branched Chain Amino Acids ◽  
Model Assessment ◽  
Waist To Hip Ratio ◽  
Branched Chain

Abstract. Branched chain amino acids (BCAA), with vitamin B6 have been reported to improve fat metabolism and muscle synthesis. We hypothesized that supplementation with BCAA and vitamin B6 would result in more weight loss and improve body composition and blood markers related to cardiovascular diseases. Our aim was to determine whether the mentioned supplementation would affect weight loss, body composition, and cardiovascular risk factors during weight loss intervention. To this end, we performed a placebo-controlled randomized clinical trial in 42 overweight and obese women (BMI = 25–34.9 kg/m2). Taking a four-week moderate deficit calorie diet (–500 kcal/day), participants were randomized to receive BCAA (6 g/day) with vitamin B6 (40 mg/day) or placebo. Body composition variables measured with the use of bioelectrical impedance analysis, homeostatic model assessment, and plasma insulin, Low density lipoprotein, High density lipoprotein, Total Cholesterol, Triglyceride, and fasting blood sugar were measured. The result indicated that, weight loss was not significantly affected by BCAA and vitamin B6 supplementation (–2.43 ± 1.02 kg) or placebo (–1.64 ± 1.48 kg). However, significant time × treatment interactions in waist to hip ratio (P = 0.005), left leg lean (P = 0.004) and right leg lean (P = 0.023) were observed. Overall, supplementation with BCAA and vitamin B6 could preserve legs lean and also attenuated waist to hip ratio.

Branched chain amino acids decrease top-down event-related potentials in healthy subjects

2007 ◽  
Vol 40 (05) ◽  
Author(s):  
AH Neuhaus ◽  
TE Goldberg ◽  
Y Hassoun ◽  
JA Bates ◽  
KW Nassauer ◽  
...  
Keyword(s):  
Amino Acids ◽  
Healthy Subjects ◽  
Event Related Potentials ◽  
Branched Chain Amino Acids ◽  
Top Down ◽  
Related Potentials ◽  
Branched Chain
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