A gel that generates nitric oxide improves microcirculatory blood flow in patients with Raynaud's syndrome, researchers say. Dr A. Tucker (clinical microvascular unit, St Bartholomew's hospital, London) and colleagues report that the gel, applied to the finger, caused significant increases in microcirculatory volume and flux in patients with Raynaud's syndrome. In a control group, flux increased but microcirculatory volume was not significantly changed (Lancet 1999;354:1670).
Raynaud's syndrome is a circulatory disorder triggered by cold or stress which results in decreased blood flow in the fingers. Dr Tucker and colleagues say that it may result from reduced sensitivity to nitric oxide or a reduction in its synthesis.
In the randomised, cross-over study of 20 patients and 10 healthy volunteers, the researchers used 0.5ml of both sodium nitrite in K-Y jelly and 0.5ml of ascorbic acid in K-Y jelly and mixed them on the skin with a cotton bud to produce nitric oxide. The mixture was then removed with a paper tissue which stopped the reaction but the effects remained at a lower level after removal. Placebo gel had no effect.
The authors comment that the nitric oxide-generating gel could be used at the time of an attack. It seemed to have no adverse effects whereas glyceryl trinitrate cream, which is also used for Raynaud's syndrome, can cause local adverse effects and also has some systemic effects. However, the nitric oxide producing gel was a messy form of treatment, they comment.