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Endothelial and adrenergic dysfunction in Raynaud's phenomenon and scleroderma.
R R Freedman1, R Girgis, M D Mayes
1Department of Psychiatry and Behavioral Neurosciences, Wayne State University School of Medicine, Detroit, Michigan, USA. aa2613@wayne.edu
The Journal of Rheumatology
|November 11, 1999
Summary
Patients with Raynaud's phenomenon (RP) and scleroderma exhibit impaired vascular responses. Endothelial dysfunction and reduced nitric oxide release may contribute to RP in scleroderma patients.
Area of Science:
- Vascular Biology
- Rheumatology
- Pharmacology
Background:
- Raynaud's phenomenon (RP) is characterized by exaggerated vasoconstriction.
- Scleroderma is associated with microvascular abnormalities and endothelial dysfunction.
Purpose of the Study:
- To investigate the roles of endothelial and adrenergic mechanisms in Raynaud's phenomenon (RP) within the context of scleroderma.
- To compare vascular responses in patients with RP and scleroderma to healthy controls.
Main Methods:
- Ten patients with RP and scleroderma and ten healthy controls were studied.
- Intra-arterial administration of methacholine, sodium nitroprusside, and clonidine.
- Bilateral finger blood flow was measured using venous occlusion plethysmography.
Main Results:
- Patients demonstrated reduced blood flow responses to methacholine (endothelium-dependent vasodilator).
- Patients showed diminished responses to clonidine (alpha2-adrenergic agonist).
- Both groups exhibited similar responses to sodium nitroprusside (endothelium-independent vasodilator).
Conclusions:
- Findings suggest impaired endothelial function and adrenergic mechanisms in scleroderma-associated RP.
- Reduced nitric oxide release from vascular endothelium may be a contributing factor to RP in these patients.
- Results align with existing histological evidence of endothelial damage in scleroderma.