Abstract
Recently, the relationship between nitric oxide (NO) and allergies has been reported. The majority of NO effects appear to be mediated by activation of guanylate cyclase (GC). Methylene blue (MB) inhibits the activity of GC when applied to the nasal mucosa of allergic rhinitis volunteers. MB inhibited the nasal provocation reaction to specific allergens. We also investigated the effect of MB on antigen induced release of histamine and leukotrienes (LTs) from human nasal polyps in vitro. MB inhibited the release of LTB4 while it did not inhibit the release of histamine and LTC4/D4/E4. MB potentially inhibits not only the release of chemical mediators, but also non specific nasal hypersensitivity.
