Changes in plasma amino acid distribution and urine amino acids excretion during prolonged heavy exercise

Refsum, H. E.; Gjessing, L. R.; Strømme, S. B.

doi:10.3109/00365517909106125

“…In our work we found a 21.4% decrease in the plasma concentration of branched chain amino acids. This data are in agreement with previous research of Blomstrand et alii (1988), Decombaz et alii (1979) and Refsum et alii (1979), but in contrast with Ahlborg et alii (1974) and Felig & Wahren (1971). The reasons for these discrepancies may be the different protocols of exercise in the last studies.…”

Section: Discussionsupporting

confidence: 92%

Effects of a competitive triathlon on plasma concentrations of tryptophan and branched-chain amino acids

Osorio

¹

,

Donoso²

1993

Rev. paul. educ. fís.

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The aim of this work was to determine the acute responses of tryptophan and branched chain amino acids to a triathlon competition. Fourteen male triathletes were studied. All took part in a international triathlon race consisting of 1,5 km swimming, 40 km biking and 10 km running. Venous blood samples were drawn before (-24 h) and after (15 min) the triathlon. Plasma concentration of branched chain amino acids and total and free tryptophan were determined. Branched chain amino acids decreased from 463 -108.3 to 364 -98.9 m ol/L (p < 0.03). Free tryptophan increases from 9.2 to 16.3 m ol/L (p < 0.006). Furthermore the ratio of free trytophan to branched chain amino acids increased from 2.07 -0.48 to 4.24 -0.79 (p < 0.001). This increases the rate of transport of tryptophan accross the blood-brain barrier and also increases the rate of synthesis of 5-hydroxytryptamine in the central nervous system. A high presence of 5-hydroxytryptamine in the brain develops physical and mental fatigue during the triathlon. This data support the participation of amino acids in fatigue process during triathlon. UNITERMS: Fatigue; Triathlon; Tryptophan.The triathlon has become one of the most popular endurance events (Osorio et alii, 1990;Osorio & Donoso, 1990). Diversity of training is indoubtedly a major reason, but the distances of competition also account for the popularity of this sport.In the ofder to be a succesfull triathlete in this sport, fatigue should be delayed in extreme. Certain amino acids can participate in this process. In fact, although amino acids are the precursors for protein synthesis, they also act as precursors for certain neurotransmitters. For example, tryptophan is converted in the brain to a neurotransmitter known as 5-hydroxytryptamine, which play a role in influencing mood.The ratio in the bloodstream of the levels of tryptophan to branched chain amino acids could control the rate of entry of tryptophan into the brain. This fact affects the concentrations of 5hydroxytryptamine and hence behaviour. A reduction in the concentration of branched amino acids in the

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“…This cycling stage does not produce haemolysis nor hem concentration as evidenced by the maintained basal values of erythrocytes and billirubin. Prolonged heavy exercise is accompanied by increased protein catabolism and changes in plasma amino acid concentrations similar to those observed during prolonged starvation, but differing from those seen at heavy exercise of less than 2 h duration or prolonged exercise of moderate intensity (Aguiló et al 2000;Refsum et al 1979). The cycling stage for about 3 h produced a decrease in some Effects of exercise and citrulline-malate supplementation on plasma urea (mg/dl) and amino acids of the urea cycle, inter organ nitrogen transport and nitrogen handling (lmol/l) determined before the race in basal conditions, immediately after the race and after 3 h of recovery…”

Section: Discussionmentioning

confidence: 95%

l-Citrulline-malate influence over branched chain amino acid utilization during exercise

Sureda

¹

,

Córdova

²

,

Ferrer

³

et al. 2010

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Exhaustive exercise induces disturbances in metabolic homeostasis which can result in amino acid catabolism and limited L-arginine availability. Oral L-citrulline supplementation raises plasma L-arginine concentration and augments NO-dependent signalling. Our aim was to evaluate the effects of diet supplementation with L-citrulline-malate prior to intense exercise on the metabolic handle of plasma amino acids and on the products of metabolism of arginine as creatinine, urea and nitrite and the possible effects on the hormonal levels. Seventeen voluntary male pre-professional cyclists were randomly assigned to one of two groups: control or supplemented (6 g L-citrulline-malate 2 h prior exercise) and participated in a 137-km cycling stage. Blood samples were taken in basal conditions, 15 min after the race and 3 h post race (recovery). Most essential amino acids significantly decreased their plasma concentration as a result of exercise; however, most non-essential amino acids tended to significantly increase their concentration. Citrulline-malate ingestion significantly increased the plasma concentration of citrulline, arginine, ornithine, urea, creatinine and nitrite (p < 0.05) and significantly decreased the isoleucine concentration from basal measures to after exercise (p < 0.05). Insulin levels significantly increased after exercise in both groups (p < 0.05) returning to basal values at recovery. Growth hormone increased after exercise in both groups, although the increase was higher in the citrulline-malate supplemented group (p < 0.05). L-citrulline-malate supplementation can enhance the use of amino acids, especially the branched chain amino acids during exercise and also enhance the production of arginine-derived metabolites such as nitrite, creatinine, ornithine and urea.

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“…In the exercising dog, net hepatic urea output increases (300), whereas in the exercising human the body urea pool has been reported to expand (239) and urea can be detected in the sweat and urine (109,236). On the other hand, an increase in ureagenesis is undetectable by use of stable isotopes (43,333) even at high work intensities (43).…”

Section: Fate Of Nitrogenous Compounds In the Livermentioning

confidence: 99%

Regulation of Extramuscular Fuel Sources During Exercise

Wasserman

¹

,

Cherrington

²

1996

Comprehensive Physiology

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The sections in this article are: Fuel Requirements of the Working Muscle Effect of Exercise Duration Effect of Exercise Intensity Exercise Responses of Hormones and Nerves Involved in Acute Metabolic Regulation Insulin Response Glucagon Response Catecholamine Responses Extramuscular Fuel Sources NEFA Mobilization from Adipose Tissue Basic Mechanisms that Influence NEFA Availability Regulatory Factors Hepatic Glucose Production Exercise Response Regulation by the Endocrine Pancreas Role of Epinephrine Role of Sympathetic Nerve Activity and Norepinephrine Role of Cortisol Regulation during High‐Intensity Exercise Hepatic Fat Metabolism: Oxidation and Triglyceride Synthesis Regulation of Ketogenesis Triglyceride Synthesis Splanchnic Bed Amino Acid Metabolism Protein Breakdown Amino Acids as a Carbon Source for Gluconeogenesis and Oxidation Uptake of Nitrogenous Compounds by the Splanchnic Bed Fate of Nitrogenous Compounds in the Liver Gastrointestinal Tract as a Source of Glucose: Effect of Carbohydrate Ingestion Importance Determinants of the Metabolic Availability of Ingested Carbohydrates Effect of Carbohydrate Ingestion on Endogenous Substrates Training‐Induced Adaptations in Extramuscular Fuel Mobilization Endocrine Adaptations to Physical Training Adaptations of Extramuscular Fuel Sources to Physical Training Summary

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Changes in plasma amino acid distribution and urine amino acids excretion during prolonged heavy exercise

Cited by 42 publications

References 24 publications

Effects of a competitive triathlon on plasma concentrations of tryptophan and branched-chain amino acids

Effects of a competitive triathlon on plasma concentrations of tryptophan and branched-chain amino acids

l-Citrulline-malate influence over branched chain amino acid utilization during exercise

Regulation of Extramuscular Fuel Sources During Exercise

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