Observation of electro-kinetic phenomena by imposing oscillating pressure and voltage gradients across some epithelial membranes.

When hydrostatic pressure across epithelia fixed between a Ussing-type chamber was oscillated mechanically, the membrane potential was found to oscillate synchronously. When the transepithelial potential was oscillated artificially, the hydrostatic pressure difference also oscillated synchronously. Under such oscillating gradient conditions, concentration changes in the unstirred layer can be minimized. Accordingly, the method using such oscillatory gradients seem to be appropriate for observation of the true streaming potential and electro-osmosis, respectively.