Document Detail

Cystine and theanine supplementation restores high-intensity resistance exercise-induced attenuation of natural killer cell activity in well-trained men.
MedLine Citation:
PMID:  20145562     Owner:  NLM     Status:  MEDLINE    
We investigated the effects of supplementation with cystine, a dipeptide of cysteine, and theanine (CT), a precursor of glutamate, on immune variables during high-intensity resistance exercise. Cysteine and glutamate are involved in the formation of glutathione, which modulates the activity of natural killer (NK) cells. In this double-blinded clinical trial, 15 well-trained men (aged 22.8 +/- 4.0 years) were divided into 2 groups: placebo (n = 7) and CT (n = 8). The placebo group was administered a powder containing cellulose (950 mg) and glutamate (30 mg), whereas the CT group was administered a powder containing cystine (700 mg) and theanine (280 mg), once daily for 2 weeks. The subjects trained according to their normal schedule (3 times per week) in the first week and trained at double the frequency (6 times per week) in the second week. Concentrations of immunoglobulin (Ig)M, interleukin (IL)-6, IL-8, and salivary IgA and the leukocyte count did not change significantly in either group. There was a significant decrease (p < or = 0.05) in the NK cell activity (NKCA) in the placebo group after the second week compared with that in the CT group (placebo: 69.2 +/- 16.1% vs. CT: 101.7 +/- 38.7%). Phytohemagglutinin-induced lymphocyte blastoid transformation did not change significantly in either group. These results suggest that NKCA is not affected in a normal training schedule with or without CT supplementation. However, high-intensity and high-frequency resistance exercises cause attenuation of NKCA, which CT supplementation appears to restore. Therefore, in practical application, CT supplementation would be useful for athletes to restore the attenuation of NKCA during high-intensity and high-frequency training.
Shigeo Kawada; Kando Kobayashi; Masaru Ohtani; Chiho Fukusaki
Publication Detail:
Type:  Controlled Clinical Trial; Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Journal of strength and conditioning research / National Strength & Conditioning Association     Volume:  24     ISSN:  1533-4287     ISO Abbreviation:  J Strength Cond Res     Publication Date:  2010 Mar 
Date Detail:
Created Date:  2010-03-02     Completed Date:  2010-05-24     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  9415084     Medline TA:  J Strength Cond Res     Country:  United States    
Other Details:
Languages:  eng     Pagination:  846-51     Citation Subset:  IM    
Laboratory of Tissue Plasticity Science, Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan.
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MeSH Terms
Cystine / pharmacology*
Dietary Supplements
Double-Blind Method
Glutamates / pharmacology*
Immunoglobulin A / analysis
Immunoglobulin M / blood
Interleukin-6 / blood
Interleukin-8 / blood
Killer Cells, Natural / drug effects*,  physiology
Leukocyte Count
Resistance Training* / adverse effects
Saliva / chemistry
Young Adult
Reg. No./Substance:
0/Glutamates; 0/Immunoglobulin A; 0/Immunoglobulin M; 0/Interleukin-6; 0/Interleukin-8; 3081-61-6/theanine; 56-89-3/Cystine

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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