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En Face Detection of Nitric Oxide and Superoxide in Endothelial Layer of Intact Arteries
Published on: February 25, 2016
Free radical-mediated lipid peroxidation and systemic nitric oxide bioavailability: implications for postexercise
Karl J New1, Michael E Reilly, Kath Templeton
1Neurovascular Research Laboratory, Faculty of Health, Science and Sport, University of Glamorgan, UK. kjnew@glam.ac.uk
American Journal of Hypertension
|February 6, 2013
Summary
Exercise lowers blood pressure in prehypertensives, linked to increased oxidative stress, not nitric oxide. This suggests a role for free radicals in postexercise hypotension.
Area of Science:
- Cardiovascular Physiology
- Exercise Science
- Hypertension Research
Background:
- The mechanisms of postexercise hypotension (PEH) are not fully understood.
- Evidence suggests pro-oxidant activity contributes to vasodilation in normotensive individuals.
- The role of oxidative stress in PEH within prehypertensive populations remains unclear.
Purpose of the Study:
- To investigate the role of oxidative stress and nitric oxide in mediating PEH in prehypertensive individuals.
- To examine hemodynamic and vascular changes following exercise in this population.
Main Methods:
- Nine prehypertensive adults underwent a cycle exercise trial and a non-exercise control trial.
- Measurements included mean arterial pressure (MAP), pulse wave velocity (PWV), vascular resistance, and conductance.
- Blood assays analyzed lipid hydroperoxides (LOOH), nitric oxide (NO), S-nitrosothiols, atrial natriuretic peptide (ANP), and angiotensin II (ANG-II).
Main Results:
- Exercise induced a significant reduction in MAP and vascular resistance post-exercise.
- Increased lipid hydroperoxides (LOOH) were observed, correlating with angiotensin II (ANG-II) levels.
- Nitric oxide (NO) and S-nitrosothiols remained unchanged, while atrial natriuretic peptide (ANP) increased.
Conclusions:
- Postexercise hypotension in prehypertensives is associated with reduced vascular resistance and elevated oxidative stress.
- The findings suggest oxidative stress, rather than nitric oxide, may play a role in the vasodilation underlying PEH.
- Further research is needed to confirm the obligatory role of free radicals in PEH.
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