Effects of halothane and enflurane on epithelium-dependent contraction and ion transport of canine tracheal epithelium

To gain insight into the cellular mechanisms involved in bronchodilation induced by inhalation anesthetics, we investigated whether halothane and enflurane can modulate functions of airway epithelium, such as epithelium-mediated bronchodilation and transepithelial transport. To measure the isometric tension of airways, paired rings of canine bronchi (4–6 mm OD), with and without the epithelium were mounted in Krebs-Ringer solution, gassed with 95% O2 and 5% CO2, and isometric tension was continuously recorded. To determine transepithelial transport, the posterior membranous portion of the trachea was mounted in Ussing-type chambers and the potential difference (PD), short-circuit current (SCC), and transepithelial resistance (R) were determined.