Serum Amino Acid Concentrations in Nine Athletes Before and After the 1993 Colmar Ultra Triathlon

Lehmann, M.; Huonker, M.; Dimeo, Fernando; Heinz, N.; Gastmann, U.; Treis, N; Steinacker, Jürgen M.; Keul, J.; Kajewski, R; Häussinger, D

doi:10.1055/s-2007-972984

Cited by 88 publications

(82 citation statements)

References 5 publications

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“…Decreases in plasma glutamine levels by intense and prolonged exercise and physical stress were demonstrated in several previous studies [61][62][63][64][65] . Also, it was reported that plasma glutamine levels were lower in athletes with "overtraining syndrome", caused by intense long-term training and associated stress, than in those who were not in a state of overtraining 66,67) .…”

Section: Taurinementioning

confidence: 89%

Exercise-induced changes in amino acid levels in skeletal muscle and plasma

Ishikura¹,

Ra²,

Ohmori³

2013

JPFSM

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During exercise, amino acid oxidation and protein breakdown are enhanced while protein synthesis is suppressed, even though protein does not constitute a quantitatively important energy source. In response to exercise-induced stimulation, various changes in free amino acids occur in skeletal muscle to meet physiological demands. Plasma amino acids are also under the influence of various types of stress, including exercise stress. For example, acute exercise increases alanine and glutamine levels, but decreases glutamate levels in skeletal muscle. At the same time, it increases tryptophan and taurine levels, but decreases glutamine levels in plasma. Prolonged exercise decreases glutamine and glutamate levels, while increasing tyrosine and phenylalanine levels in skeletal muscle. Furthermore, when prolonged exercise-induced changes in amino acid levels are compared between trained and untrained individuals, glutamate and taurine levels in skeletal muscle and phenylalanine, leucine, isoleucine, and tyrosine levels in plasma are higher in trained individuals. This review provides an overview of changes in amino acid levels in skeletal muscle and plasma, with a focus on changes induced by exercise.

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Section: Taurinementioning

confidence: 89%

Exercise-induced changes in amino acid levels in skeletal muscle and plasma

Ishikura¹,

Ra²,

Ohmori³

2013

JPFSM

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“…Second, the growth defect of the serC mutant in minimal medium does not appear to be a generalized effect but is instead largely specific to early phase and can be completely restored by the addition of exogenous serine. Third, chemical analysis of human serum suggests that the levels of exogenous free serine in human serum are unlikely to be limiting for serC mutant growth (19,29). For these reasons, we currently favor the regulatory model, which posits that serC may not simply act as a general housekeeping gene but may also be involved in the synthesis of components specifically required for B. pseudomallei virulence.…”

Section: Discussionmentioning

confidence: 99%

Global Map of Growth-Regulated Gene Expression in Burkholderia pseudomallei , the Causative Agent of Melioidosis

et al. 2006

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Many microbial pathogens express specific virulence traits at distinct growth phases. To understand the molecular pathways linking bacterial growth to pathogenicity, we have characterized the growth transcriptome of Burkholderia pseudomallei, the causative agent of melioidosis. Using a fine-scale sampling approach, we found approximately 17% of all B. pseudomallei genes displaying regulated expression during growth in rich medium, occurring as broad waves of functionally coherent gene expression tightly associated with distinct growth phases and transition points. We observed regulation of virulence genes across all growth phases and identified serC as a potentially new virulence factor by virtue of its coexpression with other early-phase virulence genes. serC-disrupted B. pseudomallei strains were serine auxotrophs and in mouse infection assays exhibited a dramatic attenuation of virulence compared to wild-type B. pseudomallei. Immunization of mice with serC-disrupted B. pseudomallei also conferred protection against subsequent challenges with different wild-type B. pseudomallei strains. At a genomic level, early-phase genes were preferentially localized on chromosome 1, while stationary-phase genes were significantly biased towards chromosome 2. We detected a significant level of chromosomally clustered gene expression, allowing us to predict ϳ100 potential operons in the B. pseudomallei genome. We computationally and experimentally validated these operons by showing that genes in these regions are preferentially transcribed in the same 533 direction, possess significantly shorter intergenic lengths than the overall genome, and are expressed as a common mRNA transcript. The availability of this transcriptome map provides an important resource for understanding the transcriptional architecture of B. pseudomallei.

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“…Frequent intense exercise and training has been shown to impair the immune response and might increase the susceptibility to infections (Castell and Newsholme, 1996). Some authors explain the increase in susceptibility to infections due to a decrease in plasma glutamine concentration, which impairs some neutrophil functions (Smith and Wilmore, 1990;Parry-Billings et al, 1992;Keast et al, 1995;Lehmann et al, 1995;Pedersen and Hoffman-Goetz, 2000). In support of this hypothesis, Nieman (1997) showed that glutamine supplementation decreased upper respiratory tract infections in athletes.…”

Section: Cell Defense and Repairmentioning

confidence: 98%

Molecular mechanisms of glutamine action

Curi

Lagranha

Doi

et al. 2005

Journal Cellular Physiology

412

300

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Glutamine is the most abundant free amino acid in the body and is known to play a regulatory role in several cell specific processes including metabolism (e.g., oxidative fuel, gluconeogenic precursor, and lipogenic precursor), cell integrity (apoptosis, cell proliferation), protein synthesis, and degradation, contractile protein mass, redox potential, respiratory burst, insulin resistance, insulin secretion, and extracellular matrix (ECM) synthesis. Glutamine has been shown to regulate the expression of many genes related to metabolism, signal transduction, cell defense and repair, and to activate intracellular signaling pathways. Thus, the function of glutamine goes beyond that of a simple metabolic fuel or protein precursor as previously assumed. In this review, we have attempted to identify some of the common mechanisms underlying the regulation of glutamine dependent cellular functions.

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Serum Amino Acid Concentrations in Nine Athletes Before and After the 1993 Colmar Ultra Triathlon

Cited by 88 publications

References 5 publications

Exercise-induced changes in amino acid levels in skeletal muscle and plasma

Exercise-induced changes in amino acid levels in skeletal muscle and plasma

Global Map of Growth-Regulated Gene Expression in Burkholderia pseudomallei , the Causative Agent of Melioidosis

Molecular mechanisms of glutamine action

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