Regulation of exercise blood flow: Role of free radicals
Joel D Trinity, Ryan M Broxterman, Russell S Richardson, Joel D Trinity, Ryan M Broxterman, Russell S Richardson
Abstract
During exercise, oxygen and nutrient rich blood must be delivered to the active skeletal muscle, heart, skin, and brain through the complex and highly regulated integration of central and peripheral hemodynamic factors. Indeed, even minor alterations in blood flow to these organs have profound consequences on exercise capacity by modifying the development of fatigue. Therefore, the fine-tuning of blood flow is critical for optimal physical performance. At the level of the peripheral circulation, blood flow is regulated by a balance between the mechanisms responsible for vasodilation and vasoconstriction. Once thought of as toxic by-products of in vivo chemistry, free radicals are now recognized as important signaling molecules that exert potent vasoactive responses that are dependent upon the underlying balance between oxidation-reduction reactions or redox balance. Under normal healthy conditions with low levels of oxidative stress, free radicals promote vasodilation, which is attenuated with exogenous antioxidant administration. Conversely, with advancing age and disease where background oxidative stress is elevated, an exercise-induced increase in free radicals can further shift the redox balance to a pro-oxidant state, impairing vasodilation and attenuating blood flow. Under these conditions, exogenous antioxidants improve vasodilatory capacity and augment blood flow by restoring an "optimal" redox balance. Interestingly, while the active skeletal muscle, heart, skin, and brain all have unique functions during exercise, the mechanisms by which free radicals contribute to the regulation of blood flow is remarkably preserved across each of these varied target organs.
Keywords: Antioxidant; Hyperemia; Oxidative stress; Redox balance; Vascular function; Vasodilation.
Published by Elsevier Inc.
Figures
![Figure 1. A conceptual schematic of the…](https://www.ncbi.nlm.nih.gov/pmc/articles/instance/4975999/bin/nihms762148f1.jpg)
![Figure 2. The relationship between net PBN…](https://www.ncbi.nlm.nih.gov/pmc/articles/instance/4975999/bin/nihms762148f2.jpg)
![Figure 3. The impact of oral antioxidant…](https://www.ncbi.nlm.nih.gov/pmc/articles/instance/4975999/bin/nihms762148f3.jpg)
![Figure 4. The Ascorbic acid-induced improvement in…](https://www.ncbi.nlm.nih.gov/pmc/articles/instance/4975999/bin/nihms762148f4.jpg)
Figure 5. A schematic of the critical…
Figure 5. A schematic of the critical link between redox balance by the exercise-induced increase…
Figure 6. Contribution of nitric oxide (NO)…
Figure 6. Contribution of nitric oxide (NO) to coronary artery cross-sectional area (CSA), flow velocity…
Figure 7. The impact of polyphenol antioxidant…
Figure 7. The impact of polyphenol antioxidant supplementation on estimated skin blood flow (SkBF) during…
Figure 8. Exercise-induced changes in ascorbate radical…
Figure 8. Exercise-induced changes in ascorbate radical (A •− ) production and associated changes in…
Figure 9. Partial correlation plot in patients…
Figure 9. Partial correlation plot in patients with Type Two Diabetes with and without hypertension…
Figure 10. Working hypothesis: Impact of alterations…
Figure 10. Working hypothesis: Impact of alterations in redox balance on free radical-induced vasodilation
The…
![Figure 5. A schematic of the critical…](https://www.ncbi.nlm.nih.gov/pmc/articles/instance/4975999/bin/nihms762148f5.jpg)
![Figure 6. Contribution of nitric oxide (NO)…](https://www.ncbi.nlm.nih.gov/pmc/articles/instance/4975999/bin/nihms762148f6.jpg)
![Figure 7. The impact of polyphenol antioxidant…](https://www.ncbi.nlm.nih.gov/pmc/articles/instance/4975999/bin/nihms762148f7.jpg)
![Figure 8. Exercise-induced changes in ascorbate radical…](https://www.ncbi.nlm.nih.gov/pmc/articles/instance/4975999/bin/nihms762148f8.jpg)
![Figure 9. Partial correlation plot in patients…](https://www.ncbi.nlm.nih.gov/pmc/articles/instance/4975999/bin/nihms762148f9.jpg)
![Figure 10. Working hypothesis: Impact of alterations…](https://www.ncbi.nlm.nih.gov/pmc/articles/instance/4975999/bin/nihms762148f10.jpg)
Source: PubMed