Effect of Electrical Current on the Secretory Status and Tissue Potassium of Amphibian Fundic Mucosa 1

Summary The effect of direct electric current (EC) on the tissue K+ concentration ([K+]t) of inhibited and secreting frog gastric mucosa was studied in order to investigate further our previous observation that a high K+ concentration in the secretory solution prevents the inhibitory effect on H+ secretion of EC passed from secretory (S) to nutrient (N) side. No differences in the [K+]t of resting, secreting or inhibited mucosae bathed with K+-free S solutions (120 mM NaCl) was observed. All N solutions contained 5 mM K+. A significant increment in [K+]t of secreting mucosae bathed on S with 100 mM KC1/20 mM NaCl was observed when EC was passed from S → N through this solution. Addition of Ba2+ (1 mM) to the N solution had no effect on [K+]t, but did prevent complete inhibition of H+ secretion by EC passed through a K+-free S solution. A mechanism whereby EC exerts its inhibitory action and the “rescue” effect of K+ on S is postulated. Interference with intracellular conductance pathways by Ba2+ on N is suggested.