Effect of glucose and diuretics on intracellular potentials of mouse intestinal mucosa.

Abstract

SummaryTo substantiate our previous hypothesis in explanation of the inhibitory effect of EA, furosemide, and amiloride on mouse intestine, the intracellular potential, Vmc, and transmural potential, Vsm, of the intestinal mucosal epithelium were measured simultaneously with a 0.5-μm diameter microelectrode. It was found when glucose was present in the Ringer bathing solution, an average Vsm of 22.5 ± 0.87 mV was recorded and Vsm was 2.68 ± 0.09 mV. EA, furosemide, and amiloride at 0.5 mM produced an hyperpolarization of Vmc and a reduction of Vsm. The Vmc increased to 34.8 ± 0.68, 31.9 ± 2.6, and 31.2 ± 0.92 mV, respectively. When the bathing fluid contained no glucose, the average Vmc was 29.5 ± 0.53 mV and the average Vsm was 1.28 ± 0.10 mV. Addition of EA in the glucose-free bathing media caused no significant change in Vmc, but a decrease in Vsm. However, addition of furosemide or amiloride did cause further hyperpolarizations of Vmc, to 40.7 ± 0.64 and 39.8 ±1.2 mV, respectively. These results suppo...