THE CONTRIBUTION OF HISTAMINE TO THE ACTION OF BRADYKININ IN THE HUMAN NASAL AIRWAY

Bradykinin, 10 to 1000 mu g given by aerosol into the nasal cavity of normal, healthy volunteers, produced a dose-related increase of nasal airway resistance. Bradykinin also reduced the minimal nasal cross-sec tional area (A,,,), increased albumin release into nasal lavage fluid and increased the symptoms of nasal inflammation. Pretreatment with ce tirizine (10 mg orally) reduced the fall in A(min) induced by bradykin in, 300 mu g, but not by bradykinin, 100 mu g. Pre-treatment of the su bjects with the H-1 histamine receptor antagonist cetirizine (10 mg, o rally) or terfenadine (60 mg, orally) 3 h before bradykinin administra tion caused significant reduction of the bradykinin-induced increase i n nasal airway resistance in the upper range of bradykinin doses (300- 1000 mu g) but not in the lower range (10-100 mu g). Cetirizine reduce d the albumin release into the nasal airway and the symptoms induced b y bradykinin, 1000 mu g. Following nasal challenge with bradykinin 300 mu g or 1000 mu g, no increase could be detected in the histamine con tent of nasal lavage fluid. Isolated human nasal cells released histam ine in response to bradykinin, 33 and 100 mu M, anti-IgE and calcium i onophore, A23187. We conclude that the actions of bradykinin in the hu man nasal airway are, in part, accounted for by the release of histami ne.