Localisation of the changes of the sensitivity of the airways by proteolytic enzymes (pronase) against acetylcholine.

Proteolytic enzymes increase the sensitivity of the bronchial system against acetylcholine when inhaled as aerosols. These experiments were performed on 33 dogs in order to localize the area of sensitivity in the bronchial system responsible fe aerosol only to the upper part of the airtract sensitises the lower part of the airways against acetylcholine. Pronase aerosol given to the lower part of the airways needs higher dosages for sensitization to acetylcholine. This effect assumes an interaction between the upper sensoric part in the reflex way of airway obstruction and the lower airways. Changes caused by proteolytic enzymes in the upper part of the airtract can cause increased reactivity of the lower airways.