Microvascular involvement in systemic sclerosis: laser Doppler evaluation of reactivity to acetylcholine and sodium nitroprusside by iontophoresis

Open Access
Publisher Website
Google Scholar
Abstract
OBJECTIVES To investigate the skin vasodilatory response to iontophoretically applied acetylcholine (Ach), an endothelium dependent vasodilator, and to sodium nitroprusside (SNP), an endothelium independent vasodilator, in patients with systemic sclerosis (SSc). METHODS Eleven SSc patients were preliminarily studied (10 females, mean age 40.5; mean disease duration 6.5 years), and 16 age and sex matched control subjects. By means of laser Doppler flowmetry skin blood flow was evaluated at third finger, at baseline, and after post-ischaemic hyperaemia test and during iontophoretically transcutaneous application of 1% solution of Ach and SNP. RESULTS No significant differences in basal skin blood flow were detected between SSc patients and controls. Cutaneous vasodilatory response to ischaemia, Ach, and SNP was significantly less pronounced in SSc patients compared with controls (pCONCLUSIONS These data confirm a reduction of skin digital vasodilatory reserve in SSc patients and suggest a defect of both endothelial dependent arteriolar relaxation and wall compliance in the pathogenesis of this dysfunction.