A new electrode for electromyographic study of bronchial smooth muscle

The contribution of the bronchial smooth muscles to asthmatic attack has been supposed by many studies such as measurement of the intrabronchial pressure and bronchographical studies, but electromyographical evidence has not been established yet. A new bipolar platinum-ring electrode fixed on polyethylene catheter was invented in order to record action potentials from the bronchial smooth muscle through the intrabronchial lead. Action potentials obtained by this electrode were compared with those obtained by the direct peribronchial needle electrode during either artificial or spontaneous respiration in dogs and a monkey. Electrophotographical analysis confirmed that action potentials obtained by our new electrode were similar in discharge pattern to those by the direct peribronchial needle electrode. The active contribution of the bronchial smooth muscle to the maintenance of the bronchial caliber during spontaneous respiration was observed by our new electrode. Accordingly, this electrode is applicable to electromyographical studies of the bronchial smooth muscle.