Nitric oxide and peroxynitrite formation in nasal secretion after allergen challenge in the allergic rhinitis / 대한이비인후과학회지

ABSTRACT

BACKGROUND AND OBJECTIVES: Recent evidence has shown that nitric oxide (NO) levels are increased in allergic rhinitis. However, the role of this molecule in the pathophysiology of allergic rhinitis is still poorly understood. Peroxynitrite (OONO-), the reactive metabolites of NO, causes nitrotyrosine formation by the nitration of tyrosine residues, and promotes deleterious effects on protein function. We attempted in this study to clarify whether NO and nitrotyrosine in the nasal secretion could be increased in the early or the late phase reaction after allergen challenge. MATERIALS AND METHODS: Samples were obtained from thirteen patients with allergic rhinits to Dermatophagoides Pteronyssinus with the filter paper absorption method. The samples were collected right before, 30 minutes after, and 8 hours after the allergen challenge. Then we estimated the concentrations of nitrite (NO2-) and nitrate (NO3-). Nitrotyrosine in nasal secretions was determined by Western blot analysis in three patients. RESULTS: The nitrite/nitrate concentration in nasal secretions did not show significant changes between the baseline, the early, and the late phase (p>0.05). In the Western blot analysis, the concentration of nitrotyrosine was increased in the late phase. CONCLUSIONS: Although the NO was not increased after the allergen challenge, nitrotyrosine, the evidence of the peroxynitrite effect to tyrosine residues of the protein, was increased in the late phase of the reaction rather than the early phase. Because the peroxynitrite is an metabolite of NO, we can estimate that the overall NO effect has an influence on the late phase of the allergic reaction, and it can be presumed that NO has an influence on the long-term deterioration on the nasal mucosa by cytotoxic effect of peroxynitrite, rather than on the immediate reaction of allergic rhinitis.