Search

Bradykinin, 10 to 1000 micrograms 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-sectional area (Amin), increased albumin release into nasal lavage fluid and increased the symptoms of nasal inflammation. Pretreatment with cetirizine (10 mg orally) reduced the fall in Amin induced by bradykinin, 300 micrograms, but not by bradykinin, 100 micrograms. Pre-treatment of the subjects with the H1 histamine receptor antgonist cetirizine (10 mg, orally) or terfenadine (60 mg, orally) 3 h before bradykinin administration caused significant reduction of the bradykinin-induced increase in nasal airway resistance in the upper range of bradykinin doses (300-1000 micrograms) but not in the lower range (10-100 micrograms). Cetirizine reduced the albumin release into the nasal airway and the symptoms induced by bradykinin, 1000 micrograms. Following nasal challenge with bradykinin 300 micrograms or 1000 micrograms, no increase could be detected in the histamine content of nasal lavage fluid. Isolated human nasal cells released histamine in response to bradykinin, 33 and 100 microM, anti-IgE and calcium ionophore, A23187. We conclude that the actions of bradykinin in the human nasal airway are, in part, accounted for by the release of histamine.

1. Acoustic rhinometry is a relatively new method for objectively assessing nasal airway patency. In this paper we compare acoustic rhinometry with active posterior rhinomanometry. 2. Twenty normal healthy volunteers underwent nasal challenge with either histamine or bradykinin, 100 micrograms to 1000 micrograms, and responses were assessed by acoustic rhinometry. A further 20 subjects received identical nasal challenges and responses were assessed by active posterior rhinomanometry. 3. On a subsequent occasion, the subjects challenged previously with histamine, were given the selective H1-receptor antagonist, cetirizine, 10 mg orally, 3 h before repeat nasal challenge with histamine, 100-1000 micrograms. Again, responses were assessed by active posterior rhinomanometry and acoustic rhinometry. 4. The acoustic reflection measurements and the nasal airway resistance measurements showed comparable, significant dose-related changes in nasal patency to both histamine and bradykinin. Pretreatment with cetirizine blocked the histamine-induced change in nasal patency as measured by both methods. 5. We conclude that acoustic rhinometry has a number of advantages over posterior rhinomanometry. It is quick to perform, requires minimal subject co-operation and gives a reliable objective, measurement of dose-related changes in nasal airway patency before and after pharmacological treatment.