The effect of N-acetyl-cysteine (Mucosolvin) on the transmural potential difference of the mucosa in children.

The mucosa of the respiratory and gastrointestinal tract produces an active transepithelial (or transmural) electric potential difference (tpd), which can be measured (in millivolts, mV). In CF-children receiving oral N-acetyl-cysteine treatment, the tpd of the buccal mucosa is largely the same as that in non-CF-children; the tpd of the nasal mucosa is significantly higher in CF-children. Given orally, N-acetyl-cysteine also provokes a significant decrease in the rectal mucosa tpd in CF-children. We suggest the effect is caused either by an osmotic effect of N-acetyl-cysteine (local), and/or by alteration of the factors regulating basal electrolyte transport/conductance of epithelia (chloride secretion? leaky junction?).