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This Article Full Text Full Text (PDF) All Versions of this Article: 297/5/H1870    most recent 00709.2009v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Wray, D. W. Articles by Richardson, R. S. PubMed PubMed Citation Articles by Wray, D. W. Articles by Richardson, R. S.

Antioxidants and aging: NMR-based evidence of improved skeletal muscle perfusion and energetics

¹Department of Medicine, University of California San Diego, La Jolla, California; ²Nuclear Magnetic Resonance Laboratory, Association Institute de Myologie-Commissariat à l'Energie Atomique, Institute de Myologie, Pitié Salpêtrière University Hospital, Paris, France; and ³Department of Internal Medicine, Division of Geriatrics, University of Utah, ⁴Department of Exercise and Sport Science, University of Utah, and ⁵Geriatric Research and Clinical Center, Salt Lake City Veterans Affairs Medical Center, Salt Lake City, Utah

Submitted July 30, 2009 ; accepted in final form September 15, 2009

We sought to examine the potential role of oxidative stress on skeletal muscle function with advancing age. Nuclear magnetic resonance (NMR) was employed to simultaneously assess muscle perfusion (arterial spin labeling) and energetics (³¹P NMR spectroscopy) in the lower leg of young (26 ± 5 yr, n = 6) and older (70 ± 5 yr, n = 6) healthy volunteers following the consumption of either placebo (PL) or an oral antioxidant (AO) cocktail (vitamins C and E and -lipoic acid), previously documented to decrease plasma free radical concentration. NMR measurements were made during and after 5 min of moderate intensity (5 W) plantar flexion exercise. AO administration significantly improved end-exercise perfusion (AO, 50 ± 5, and PL, 43 ± 4 ml·100 g^–1·min^–1) and postexercise perfusion area under the curve (AO, 1,286 ± 236, and PL, 866 ± 144 ml/100 g) in older subjects, whereas AO administration did not alter hemodynamics in the young group. Concomitantly, muscle oxidative capacity (time constant of phosphocreatine recovery, ) was improved following AO in the older (AO, 43 ± 1, and PL, 51 ± 7 s) but not the young (AO, 54 ± 5, and PL, 48 ± 7 s) group. These findings support the concept that oxidative stress may be partially responsible for the age-related decline in skeletal muscle perfusion during physical activity and reveal a muscle metabolic reserve capacity in the elderly that is accessible under conditions of improved perfusion.

leg blood flow; oxidative capacity; exercise; nuclear magnetic resonance