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Ultrasound Assessment of Endothelial-Dependent Flow-Mediated Vasodilation of the Brachial Artery in Clinical Research
Published on: October 22, 2014
Enhanced cholinergic cutaneous vasodilation in Raynaud's phenomenon
1Peripheral Vascular Section, Evans Memorial Department of Clinical Research, Boston University Medical Center, MA.
Circulation
|March 1, 1994
Summary
Patients with Raynaud's phenomenon exhibit enhanced fingertip and forearm skin vasodilator responses to methacholine, suggesting increased cutaneous blood vessel responsiveness. This may relate to the pathophysiology of vasospasm in Raynaud's phenomenon.
Area of Science:
- Vascular physiology
- Dermatology
- Cardiovascular research
Background:
- Raynaud's phenomenon is characterized by exaggerated vasoconstriction.
- Understanding vasodilator function is crucial for managing this condition.
- Endothelium-dependent and -independent vasodilators are key to assessing vascular function.
Purpose of the Study:
- To determine vasodilator function in patients with Raynaud's phenomenon.
- To compare responses to endothelium-dependent (methacholine) and -independent (sodium nitroprusside) vasodilators.
- To investigate reactive hyperemia in patients with Raynaud's phenomenon.
Main Methods:
- Intra-arterial infusions of methacholine and sodium nitroprusside.
- Venous occlusion plethysmography for fingertip and forearm blood flow.
- Laser Doppler flowmetry for forearm skin blood flow.
- Measurement of reactive hyperemia after arterial occlusion.
Main Results:
- Patients with Raynaud's phenomenon showed a significant increase in fingertip blood flow with methacholine, unlike controls.
- Forearm skin blood flow demonstrated a greater vasodilator response to methacholine in Raynaud's patients.
- Total forearm blood flow and reactive hyperemia responses were similar between groups for both vasodilators.
Conclusions:
- Raynaud's phenomenon is associated with enhanced vasodilator responses in fingertip and forearm skin.
- This suggests increased responsiveness of cutaneous blood vessels to endothelial stimulation in Raynaud's.
- The underlying mechanism may involve a generalized abnormality of skin blood vessels related to vasospasm.
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