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Author Notes:

Correspondence: Dean P. Jones, Ph.D., Div. Pulmonary Medicine/Dept of Medicine, 615 Michael Street, Suite 205P, Emory University, Atlanta, GA 30322; Tel: +1-404-727-5970; Fax: +1-404-712-2974; Email: dpjones@emory.edu

Author's Contributions: CA, TZ, XH and DJ participated in study design and analytic supervision.

YP, SK, and TZ participated in data interpretation, biostatistics and bioinformatics analysis.

NM and TZ participated in subject recruitment and clinical aspects of the study.

YP, CA, TZ and DJ participated in manuscript preparation.

Acknowledgments: The authors thank the GCRC nursing staff and Jennifer Terry, R.D., Margaret Pedersen, R.D, Vera Hull and Diane Harris of the GCRC Bionutrition Unit for preparation of the study diets.

Disclosures: The authors had no conflicts of interest.

Subjects:

Research Funding:

This research was supported by NIH grants ES012929 and ES009047 (DPJ), DK55850 and K24 RR023356 (TRZ) and Emory General Clinical Research Center grant M01 RR00039/UL1 RR025008.

Keywords:

  • Brain metabolism
  • oxidative stress
  • amino acid metabolism
  • nutritional assessment
  • protein malnutrition
  • glutathione

Sulfur amino acid-free diet results in increased glutamate in human midbrain: a pilot magnetic resonance spectroscopic study

Tools:

Journal Title:

Nutrition

Volume:

Volume 28, Number 3

Publisher:

, Pages 235-241

Type of Work:

Article | Post-print: After Peer Review

Abstract:

Objective This pilot study was designed to determine if metabolic effects in different brain regions (left and right parietal lobes, midbrain) due to 3 days of food consumption without methionine or cysteine could be detected by proton magnetic resonance spectroscopy (MRS). Research Methods & Procedures Healthy individuals aged 18-36 y (n=8) were studied by MRS after receiving diet with adequate sulfur amino acids (SAA) or with zero SAA for 3 days. Pulse sequences were used to selectively measure glutathione (GSH) and linear combination modeling (LCM) of spectra was used to measure other high abundance brain metabolites, and expressed relative to creatine (Cr). Results Although dietary SAA are required to maintain glutathione (GSH), the 3-d SAA insufficiency resulted in no significant change in GSH/Cr in the three brain regions. Principal component analysis of 16 metabolites measured by LCM showed that the metabolic pattern in the midbrain, but not the parietal lobes, was distinguished according to the dietary SAA. Multivariate statistical analysis showed that the major discriminating factors were signals of glutamate/Cr, (glutamate+glutamine)/Cr, and myo-inositiol/Cr. Correlation analyses between midbrain metabolites and GSH-related metabolites in plasma showed that midbrain glutamate/Cr had an inverse correlation with plasma cystine. Conclusion The data show that MRS is a non-invasive tool suitable for nutritional assessment and suggest that nutritional imbalance caused by 3-d of sulfur amino acid-free food more selectively affects midbrain than the parietal lobes.

Copyright information:

© 2012, Elsevier

This is an Open Access work distributed under the terms of the Creative Commons Attribution-NonCommerical-NoDerivs 3.0 Unported License (http://creativecommons.org/licenses/by-nc-nd/3.0/).

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