Effect of hydrogen peroxide on guinea pig nasal mucosa vasculature

The effect of hydrogen peroxide (H2O2) on guinea pig nasal mucosa vasculatu re was studied by in vitro assay. H2O2 elicited relaxation of guinea pig na sal mucosa strips precontracted with phenylephrine in a concentration-depen dent manner. The relaxant response to H2O2 was abolished in the presence of catalase. Preincubation of the strips with NG-nitro-L-arginine methyl este r or methylene blue significantly attenuated the relaxant responses elicite d by H2O2 Fluorescence caused by DAF-2 DA, a fluorescence indicator for nit ric oxide, was observed along the nasal mucosa vasculature in response to H 2O2. These results suggest that H2O2 induced relaxation of the guinea pig n asal mucosa vasculature and that this relaxation is mediated by the NO/cGMP pathway.