Nitric Oxide May Play A Role In The Rosacea Picture

Dr. Ethan A. Lerner, associate professor of Dermatology, Harvard Medical School.

In research funded by the National Rosacea Society, Dr. Lerner examined the potential contribution of nitric oxide to the redness and inflammation of rosacea. Nitric oxide is a gas produced naturally in nearly all of the body's cells and is used by the nervous, immune and cardiovascular systems. Because nitric oxide is known to make blood vessels dilate, it was hypothesized that it may play a role in rosacea.

The study aimed to test for the presence of nitric oxide synthase (NOS), a nitric oxide-producing enzyme, and the gene that creates NOS in the skin of rosacea patients through in situ hybridization and immunoperoxidase.

The in situ hybridization test was inconclusive; the researchers had difficulty obtaining clean results from the probes, and high background levels made it difficult to isolate NOS readings.

In the immunoperoxidase test, stains of biopsies taken from the skin of rosacea patients showed a normal amount of NOS. This could be interpreted as indicating that nitric oxide is not a significant factor in rosacea. However, Dr. Lerner believes that different types and severities of rosacea should be tested before the molecule can be completely ruled out.

The researchers also determined how much of a known nitric oxide inhibitor is absorbed through the skin, so that the effects of suppressing nitric oxide might be tested.

In other research, Dr. Lerner is developing a mouse model of what happens in human skin when too much nitric oxide is present. He is attempting to produce transgenic mice in which the gene for NOS is expressed in the skin under the control of a promoter, so that application of a topical compound will cause production of nitric oxide. Among the potential outcomes to be observed is whether too much nitric oxide produces any signs of rosacea.