Role of Epithelial Sodium Channel in the Realization of Homeostatic Effects of Aldosterone on the Volume of Principal Cells of Cortical Collecting Ducts in Rats after Hypoosmotic Stress

The mechanism of aldosterone effects (10 nM) on the volume of the principal cells of cortical collecting ducts after hypoosmotic stress (280/140 mOsm/kg) was studied using fluorescence microscopy. The experiments with intracellular fluorescent dye calcein showed that aldosterone significantly decreases the amplitude and rate of increase in principal cell volume during hypoosmotic stress. Epithelial sodium channel blocker amiloride (10 -5 M) significantly attenuated the effects of aldosterone on the amplitude and rate of changes in cell volume. The obtained data attest to the contribution of epithelial sodium channel to the realization of rapid non-genomic effects of aldosterone on the amplitude and rate of changes in volume of the principal cells of cortical collecting ducts in rat kidney after hypoosmotic stress.