Transepithelial electrophysiological parameters in rabbit respiratory nasal mucosa isolated In vitro

1. 1. Transepithelial electrical p.d. (Vms), short circuit current (Isc) and transepithelial resistance (Rep) were determined in rabbit nasal mucosa and were compared with the equivalent parameters of human nasal mucosa. 2. 2. Vms-4 was about 1 mV (submucosa positive) in the absence of glucose, but increased continuously in the presence of glucose. Since Isc also increased in parallel and Rep remained constant (about 40 Ω cm2), glucose effect was to power pumping. 3. 3. Diffusion potentials raised by reducing luminal Cl− or Na+ or Cl− and Na+ concentrations were also measured and compared with values obtained in trachea and gallbladder. 4. 4. Evidence is produced, with sounder basis than in trachea, that junctional pathways in airway epithelia are lined with fixed positive charges (which make anions more permeable than cations), unlike junctional pathways of the gastrointestinal tract which are lined with fixed negative charges.