Antigen-induced airway obstruction and the influence of vagus blockade

Respiratory hypersensitivity to Ascaris antigens is carried out on 9 dogs. The participation of vagus reflex on this respiratory distress is studied in 4 of these dogs. The dogs were exposed initially to Ascaris aerosol, then to egg albumin and NaCl aerosol for control, and once more to Ascaris aerosol after bilateral vagi blockade and lavage, respectively. The principal parameters studied were deltaPoes (mm Hg)/100 ml TV as a measurement of flow resistance in the airways, and respiratory rates (Poes=changes of oesphagus pressure; TV=tidal volume). All the animals presented a significant respiratory distress with Ascaris aerosol, which could be clearly avoided with the central bilateral blockade of nervus vagus.