The bronchoconstrictor action of bradykinin in the guinea-pig.

Bradykinin was found to be a potent bronchoconstrictor agent in the guinea-pig anaesthetized with urethane. This action was not affected by vagotomy, or by treatment of the animal with mepyramine, atropine, lysergic acid diethylamide, or cortisone. Adrenaline and isoprenaline suppressed the bronchoconstrictor responses to bradykinin and histamine. Small doses of acetylsalicylic acid, however, suppressed only that to bradykinin. Bradykinin also produced bronchoconstriction in the isolated perfused lungs of the guinea-pig. The closely related peptide, wasp kinin, was also a potent bronchoconstrictor.