The possible role of bradykinin as a mediator in bronchial asthma.

A variety of antiasthmatic drugs were examined in a bioassay of uterine cornua of rats for determining their influence upon Bradykinin induced contractions. 4 different actions were seen: pronounced, moderate and weak suppression of enhancement of Bradykinin-activity. The most pronounced blocking effect was seen with Fenoterol, Adrenaline and Pheniramine, a moderate effect with Prednisolone and Tolazoline, a weak effect with Propranolol and DSCG. Noradrenaline showed a stimulating effect. It is postulated that Bradykinin acts via alpha-stimulation with concomitant cAMP-decrease after specific binding to Bradykinin-receptors. The results of the study suggest that Bradykinin still must be discussed as a possible mediator in obstructive airway-disease.