1. Effect of Glucose and Diuretics on Intracellular Potentials of Mouse Intestinal Mucosa1
- Author
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Dinno, M. A. and Huang, K. C.
- Abstract
To 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 Vsmof 22.5 ± 0.87 mV was recorded and Vsmwas 2.68 ± 0.09 mV. EA, furosemide, and amiloride at 0.5 mMproduced an hyperpolarization of Vmcand a reduction of Vsm. The Vmcincreased 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 Vmcwas 29.5 ± 0.53 mV and the average Vsmwas 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 support our conclusion that EA mainly acts on the Na-glucose co-transport system and the other two diuretics act on the membrane conductance. The Ar-rhenius plots of the variations of Vsmand Vmcwith temperature provide the calculation of the activation energies for the trans-mural and transmucosal potentials as 19.3 and 14.02 kcal/mole, respectively.
- Published
- 1977
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