| Sign In to gain access to subscriptions and/or personal tools. |
Mechanisms of Raynauds diseaseSection of Vascular Medicine, Stanford University School of Medicine, Stanford, California, USA, john.cooke{at}stanford.edu
Department of Physiology, Division of Medical Sciences, The Medical School, University of Birmingham, Birmingham, UK, Head of the Department of Physiology and of the Division of Medical Sciences, The Medical School, Birmingham, UK, j.m.marshall{at}bham.ac.uk Raynaud's phenomenon is due to transient cessation of blood flow to the digits of the hands or feet. An attack of Raynauds phenomenon is classically manifested as triphasic color changes. The white phase is due to excessive vasoconstriction and cessation of regional blood flow. This phase is followed by a cyanotic phase, as the residual blood in the finger desaturates. The red phase is due to hyperemia as the attack subsides and blood flow is restored. An attack is frequently associated with pain and/or paresthesia due to sensory nerve ischemia. Variants of Raynauds phenomenon include acrocyanosis and primary livedo reticularis, each of which is associated with reduced skin blood flow, exacerbated by cold or emotional upset. Raynauds phenomenon in the absence of other disorders is primary Raynauds phenomenon, or Raynauds disease. The mechanisms of Raynauds disease include increased activation of the sympathetic nerves, in response to cold or emotion; an impaired habituation of the cardiovascular response to stress may contribute. In addition, there appears to be a local fault, which is likely multifactorial. This local fault is due to an alteration in vascular function rather than vascular structure. The alteration in vascular function may be related to increased sensitivity to cold of the adrenergic receptors on the digital artery vascular smooth muscle. In some cases, locally released or systemically circulating vasoconstrictors may participate, including endothelin, 5-hydroxytryptamine and thromboxane. A deficiency or increased degradation of nitric oxide, possibly due to increased oxidative stress, may be involved in some cases. These recent pathophysiological insights may lead to new therapeutic options.
Key Words: acrocyanosis alpha-adrenoreceptors endothelium estrogen thermo-regulation vasospasm
Vascular Medicine, Vol. 10, No. 4,
293-307 (2005) This article has been cited by other articles:
|
|||||||||||||||
