Bradykinin-induced airway contraction in two lines of guinea pigs with congenitally different airway sensitivity

The airway responsiveness to bradykinin (0.1, 1 and 10 mu g/kg, i.v.) was examined in two lines of guinea pigs, BHS (bronchial hypersensitive) and BHR (bronchial hyposensitive) lines, with different airway sensitivity to inhalation of acetylcholine (ACh)-aerosol. Normal Hartley strain guinea pigs were used as a control group. The airway contraction was measured by recording intratracheal pressure (P-IT) and respiratory airflow ((V) over dot) under the condition of artificial ventilation in anesthetized guinea pigs. The results show airway responsiveness to bradykinin in BHS guinea pigs to be significantly greater than in BHR and normal Hartley strain guinea pigs.