Impedance of the frog gastric mucosa, the Teorell-Wersäll effect

The small signal impedance of frog gastric mucosa has been measured from 1 Hz to 500 kHz. The results obtained in Ringer's solution have been compared with the effect of replacing sodium with potassium on the nutrient side of the mucosa. The substitution to potassium reduces the membrane resistance and changes the impedance locus from a flat to a semicircular shape. We have examined this effect, the Teorell-Wersäll effect, in relation to changes in membrane permeabilities. The experimental data are consistent with a model based on the electrical behaviour of transmission cables (the geometric requirement for this may be found in the gastric duct) and the observed electrical properties can be predicted from an increase in conductance of the secretory membrane when replacing sodium with potassium.