Responses to nasal bradykinin challenge in normal and allergic subjects

Abstract

Problem: Neurally mediated secretory hyper-reactivity is well-documented in allergic rhinitis; however, congestive responses to nasal challenge in allergic subjects are less well characterized. Methods: Normal subjects (n = 13), and subjects with seasonal allergic rhinitis (SAR) (n = 16), perennial allergic rhinitis (PAR) (n = 24), and nonallergic rhinitis (NAR) (n = 9) underwent unilateral nasal challenge with Hartman’s solution, bradykinin 50 mcg, and bradykinin 100 mcg. Acoustic rhinometry was performed at baseline and after each challenge. Values for the first, second, and third minimum cross-sectional areas (csa 1, 2, 3), and the volumes to csa 2, csa 3, and to 4 cm inside the nasal cavity (vol 2, 3, 4) were recorded on each side. Results: Challenge with the first dose (50 mcg) of bradykinin in normal subjects led to ipsilateral congestion. A tendency to decongest was seen after the second (100 mcg) dose. Significant changes were not seen in contralateral parameters. In contrast, subjects with SAR and PAR demonstrated significant contralateral congestion after control challenge, which persisted after both bradykinin challenges. Subjects with SAR also demonstrated significant ipsilateral congestion after challenge with bradykinin 50 mcg; however, this was not the case for subjects with PAR. Subjects with NAR did not demonstrate any significant ipsilateral or contralateral congestive responses. Conclusion: Acoustic rhinometry may be used to measure congestive responses to nasal bradykinin challenge. Allergic subjects demonstrate congestive hyper-reactivity, which is more pronounced on the contralateral side. Subjects with PAR had a less pronounced ipsilateral congestive response than did normal subjects or subjects with SAR, which may reflect greater baseline nasal congestion or disturbed regulation of nasal mucosal blood flow. Significance: The present study is the first to investigate nasal congestive responses to bradykinin challenge using acoustic rhinometry in a large number of subjects. Our findings suggest that hyper-reactive congestive reflexes may contribute to the symptoms of allergic rhinitis. Support: None reported.