LONDON, UNITED KINGDOM. Raynaud's syndrome afflicts between 3 and 20 per cent of all adults and is more common by a ten to one ratio among women than among men. The condition is characterized by a disruption of the blood flow to fingers or toes resulting in cold, numbness, pain, and a characteristic white/blue colour of the affected parts. Avoidance of smoking, keeping warm, and the use of slow-acting calcium-channel- blockers are recommended, but not always successful therapies for the condition. There is some indication that Raynaud's syndrome involves an abnormality in the synthesis and inactivation of nitric oxide, a potent dilator of blood vessels.
Now researchers at St. Bartholomew's Hospital in London report that the application to the skin of a simple gel formulated to generate nitric oxide can markedly improve blood flow to the treated area. Their experiment involved 20 patients with severe, primary Raynaud's syndrome (Raynaud's disease) and 10 healthy volunteers. The nitric-oxide-generating system was prepared by mixing 0.5 mL of a jelly (KY jelly) containing 5 per cent sodium nitrite with 0.5 mL of a jelly containing 5 per cent ascorbic acid right on the skin or fingertip of the participants covering an area of about three square centimeters. The resulting reaction between the sodium nitrite and ascorbic acid was stopped after a few seconds by simply wiping the gel off with a paper tissue. The effect of the jelly on its own (placebo treatment) was tested in a similar way.
Blood flow in the treated areas was measured with infrared photoplethysmography and
laser doppler fluxmetry. The researchers found no difference in baseline blood flow
(microcirculatory volume and flux) in the forearm skin between the Raynaud's patients and
the healthy controls. However, the Raynaud's patients had a significantly lower blood flow
in the finger tips before application of the gel than did the controls. Application of the
nitric-oxide-generating gel increased blood flow very significantly in both patients and
controls. The increase in the treated forearm area was six- to ten-fold and on the
fingertips about three-fold. The researchers conclude that application of the nitric-oxide-
generating gel at the time of an attack is a simple, effective, and safe treatment of severe
vasospasm associated with Raynaud's syndrome.