| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Department of Medicine, UC San Diego, La Jolla, California, United States
2 Medicine, UC San Diego, Department of Medicine, La Jolla, California, United States
3 Medicine, University of California San Diego, La Jolla, California, United States
4 Department of Medicine, University of California San Diego, La Jolla, California, United States
5 School of Applied Sciences, Hypoxia Research Unit, Mid-Glamorgan, United Kingdom
* To whom correspondence should be addressed. E-mail: rrichardson{at}ucsd.edu.
Originally thought of as simply damaging or toxic "accidents" of in vivo chemistry, free radicals are becoming increasingly recognized as redox signalling molecules implicit in cellular homeostasis. Indeed at the vascular level it is plausible that oxidative stress plays a regulatory role in normal vascular function. Using electron paramagnetic resonance (EPR) spectroscopy, we sought to document the ability of an oral antioxidant cocktail (Vitamins C, E and 
-lipoic acid) to reduce circulating free radicals and employed Doppler ultrasound to examine the consequence of an anti-oxidant mediated reduction in oxidative stress on exercise-induced vasodilation. A total of 25 young (18-31 yrs) healthy male subjects partook in these studies. EPR spectroscopy revealed a reduction in circulating free radicals following antioxidant administration at rest (~98%) and as a consequence of exercise (~85%). Plasma total antioxidant capacity and Vitamin C both increased following the ingestion of the antioxidant cocktail, while Vitamin E levels were not influenced by the ingestion of the antioxidants. Brachial artery vasodilation during sub-maximal forearm handgrip exercise was greater with the placebo (7.4 ± 1.8 %) than with the antioxidant cocktail (2.3 ± 0.7 %). These data document the efficacy of an oral antioxidant cocktail in reducing free radicals and suggest that in a healthy state the aggressive disruption of the delicate balance between pro and antioxidant forces, can negatively impact vascular function. These findings implicate an exercise-induced reliance upon pro-oxidant stimulated vasodilation thereby revealing an important and positive vascular role for free radicals.
This article has been cited by other articles:
|
|
 |
|
  D. W. Wray, S. K. Nishiyama, A. Monnet, C. Wary, S. S. Duteil, P. G. Carlier, and R. S. Richardson Antioxidants and aging: NMR-based evidence of improved skeletal muscle perfusion and energetics Am J Physiol Heart Circ Physiol, November 1, 2009; 297(5): H1870 - H1875. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. W. Copp, L. F. Ferreira, K. F. Herspring, D. M. Hirai, B. S. Snyder, D. C. Poole, and T. I. Musch The effects of antioxidants on microvascular oxygenation and blood flow in skeletal muscle of young rats Exp Physiol, September 1, 2009; 94(9): 961 - 971. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. E. Pyke, V. Poitras, and M. E. Tschakovsky Brachial artery flow-mediated dilation during handgrip exercise: evidence for endothelial transduction of the mean shear stimulus Am J Physiol Heart Circ Physiol, June 1, 2008; 294(6): H2669 - H2679. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. L. Clanton Hypoxia-induced reactive oxygen species formation in skeletal muscle J Appl Physiol, June 1, 2007; 102(6): 2379 - 2388. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| Visit Other APS Journals Online |
