The electrophysiological properties of the mucosal barrier in the injured mouse jejunum in Ussing chambers.

We previously suggested in the in vitro mouse jejunum that when the primary epithelial barrier on the villi was largely disabled, a secondary mucosal barrier substitutes for the primary one. This study showed that the mucosal Ca(2+) removal did not further deteriorate the histology but increased transmural conductance and lucifer yellow flux, and decreased forskolin-induced potential difference. It is suggested that in this injury model the postulated secondary barrier is Ca(2+)-dependent and likely to be present on or immediately beneath the mucosal surface.