Ambroxol effect on transepithelial electrical potential difference of isolated tracheal wall

The effect of ambroxol on ion transport in isolated tracheal wall was studied by the electrophysiological (Ussing) method. It was shown that ambroxol influenced one component of the transepithelial electrical potential difference (PD), which is related to ion transport processes mechanically stimulated by a jet of bathing fluid from a peristaltic pump. The other component of the PD, which represented stable ion transport processes, was not influenced by the drug. The stimulation-dependent component of the PD was deeply inhibited, or sometimes even eliminated, by a change in the pH of the stimulating bathing fluid from 7.4 to 6.4. Ambroxol, in a concentration of 5 microM, restored the mechanical reactivity of tissue stimulated by jet of fluid at pH 6.4. We put forward the hypothesis that ambroxol influences the ion transport processes, which are evoked by stimulation of "cough receptors", in a way that probably augments airway cough clearance.