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CD4(+)/CD8(+) T-lymphocyte Ratio: Effects of Rehydration before Exercise in Dehydrated MenEffects of fluid ingestion on CD4+/CD8+ T-lymphocyte cell ratios were measured in four dehydrated men (ages 30-46 yr) before and after 70 min of supine submaximal (71 % VO(sub 2max) lower extremity cycle exercise. Just before exercise, Evans blue dye was injected for measurement of plasma volume. The subjects then drank one of six fluid formulations (12 ml/kg) in 3-4 min. All six mean post-hydration (pre-exercise) CD4+/CD8+ ratios (Becton-Dickinson Fluorescence Activated Cell Sorter and FACScan Consort-30 software program were below the normal range of 1.2-1.5; mean (+/- SE) and range were 0.77 +/- 0.12 and 0.39-1.15, respectively. The post-exercise ratios increased: mean = 1.36 =/- 0.15 (P less than 0.05) and range = 0.98-1.98. Regression of mean CD4+/CD8+ ratios on mean plasma osmolality resulted in pre- and post-exercise correlation coefficients of -0.76 (P less than 0.10) and -0.92 (P less than 0.01), respectively. The decreased pre-exercise ratios (after drinking) were probably not caused by the Evans blue dye but appeared to be associated more with the stress (osmotic) of dehydration. The increased post-exercise ratios to normal levels accompanied the rehydration and were not due to the varied electrolyte and osmotic concentrations of the ingested fluids or to the varied vascular volume shifts during exercise. Thus, the level of subject hydration and plasma osmotality may be factors involved in the mechanism of immune system modulation induced by exercise.
Document ID
Document Type
Reprint (Version printed in journal)
Greenleaf, John E. (NASA Ames Research Center Moffett Field, CA United States)
Jackson, Catherine G. R. (University of Northern Colorado Greeley, CO United States)
Lawless, Desales (Rockefeller Univ. New York, NY United States)
Date Acquired
August 17, 2013
Publication Date
January 1, 1995
Publication Information
Publication: Medicine and Science in Sports and Exercise
ISSN: 0195-9131
Subject Category
Life Sciences (General)
Report/Patent Number
NAS 1.15:112677
Funding Number(s)
PROJECT: RTOP 199-18-12-07
Distribution Limits
Public Use Permitted.
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