Basic electrical properties of tight epithelia determined with a simple method.

A simple method for the routine mounting of epithelia which greatly reduces or eliminates faulty sealing at the edge is described. The values of potential and resistance observed in the frog skin and toad urinary bladder are comparable to those found with more complicated methods designed to minimize edge damage. In agreement with observations in other epithelia, a direct relationship between short circuit and conductance is observed for frog skin and toad urinary bladder, implying that the relationship is a general feature of tight epithelia. Furthermore, the high values of transepithelial resistance imply that the lower limit for the paracellular shunt pathway resistance should be reset upwards.