Electrical Impedance Properties of Surviving Gastric Mucosa of the Frog

Abstract

Summary. The alternating current impedance of the isolated, surviving stomach mucosa from frog was examined over the frequency range 10–13,000 c/s. The results were expressed in terms of impedance locus diagrams according to GILDEMEISTER‐LULLIESCOLE. In general it was found that different states of activity and external conditions had a marked influence on the impedance quantities such as the “parallel resistance” and the “polarization angle”. On the whole, it was found that strong stimulation (in connection with secretion, or electrical current flow) or injury (mechanical or chemical) in particular affected the parallel resistance. Impedance quantities related to the polarization properties of the mucous membrane, i. e. the “polarization angle” and the “characteristic frequency”, were sensitive to the exchange of sodium ions against potassium ions (“potassium effect”). The observations are discussed according to some current hypotheses. It is emphasized that great caution must be exercised when attempting to interpret the impedance quantities in terms of cell and tissue permeability.