Related Experiment Videos
Limb blood flow during exercise is dependent on nitric oxide
A J Maxwell1, E Schauble, D Bernstein
1Section of Vascular Medicine, Stanford University, Calif 94305-5246, USA.
Circulation
|August 26, 1998
Summary
Endothelium-derived nitric oxide (EDNO) is crucial for exercise limb blood flow. Reduced EDNO production, seen in hypercholesterolemia, impairs exercise capacity by disrupting blood flow regulation.
Area of Science:
- Cardiovascular Physiology
- Exercise Science
- Nitric Oxide Biology
Background:
- Hypercholesterolemia is linked to reduced aerobic exercise capacity in mice.
- This reduction is associated with impaired endothelium-dependent vasodilation and nitric oxide (NO) production.
Purpose of the Study:
- To test if EDNO significantly contributes to limb blood flow during exercise.
- To determine if diminished EDNO production causes exercise intolerance in hypercholesterolemia.
Main Methods:
- Treadmill testing in wild-type and apoE-deficient mice to assess exercise capacity and urinary nitrate excretion.
- Pharmacological inhibition of NO synthesis using nitro-L-arginine (LNA) in wild-type mice.
- Measurement of blood flow to running muscles using fluorescent microspheres during exercise.
Main Results:
- Both LNA-treated wild-type mice and apoE-deficient mice showed reduced post-exercise urinary nitrate excretion.
- These groups also exhibited significantly lower aerobic capacity and muscle blood flow during peak exercise compared to control wild-type mice.
Conclusions:
- EDNO plays a significant role in regulating limb blood flow during physical exertion.
- Conditions that decrease EDNO production compromise the exercise hyperemic response, leading to reduced exercise capacity.