Electrical properties of renal collecting duct principal cell epithelium in tissue culture.

Whereas collecting duct epithelium in vivo is composed of principal and intercalated cells, we grew a pure principal cell epithelium using a new technique involving tissue culture. These principal cells were derived from collecting duct anlagen of newborn rabbits. We investigated the electrical properties of such epithelia in a newly designed lucite double-chamber with an inner opening of 0.08 cm2. Our observations were: mean transepithelial resistance Rte was 0.83 +/- 0.2 k omega cm2 at 37 degrees C and after preincubation in aldosterone; mean transepithelial potential difference Vte was low and variable under standard conditions and at room temperature but increased to -59.5 +/- 4.4 mV (sign referring to polarity of apical surface) after preincubation in 10(-6) mol/l aldosterone and at 37 degrees C; 10(-6) mol/l amiloride added to the apical perfusion fluid largely abolished this Vte while increasing Rte by 120%; experiments with 5 X 10(-3) mol/l BaCl2 in the apical perfusion fluid failed to change Rte and Vte significantly. This principal cell epithelium therefore has characteristics of a "tight" epithelium with active sodium transport; however, its electrical properties differ from those of the isolated perfused collecting duct segment.