EDN1 and airway hyperresponsiveness: These finding support those of others where inhibition of ET‐1 with BQ‐123 and a dual ETA and ETB blockade with SB‐209670, reduced airway eosinophilia and neutrophilia in ovalbumin‐sensitized mice.43 Furthermore, in a mouse model of house dust mite sensitization, eosinophilia and airway hyperresponsiveness were alleviated by the dual ET‐1 receptor antagonist SB‐217242.44 Interestingly, eosinophil cell count was not significantly reduced by BQ‐123 in the current study although there was only a modest increase with culture filtrate exposure.