Insulin decreases apical cell membrane resistance in cultured kidney cells (A6).

Intracellular potentials measured across the apical and basolateral cell membranes of cultured renal A6 cells were -53.5 +/- 1.5 and -48.7 +/- 1.3 mV, respectively, (19 measurements) and did not significantly change after insulin treatment. Analysis based on an equivalent circuit indicates that the resistances of the apical cell membrane and of the transcellular pathway decrease after insulin treatment to 36 +/- 6 and 42 +/- 6% of the control value respectively (7 measurements). Thus, the decrease in transcellular resistance which accompanies an increase in transcellular Na transport after insulin treatment appears to be connected with a commensurate decrease in apical cell membrane resistance.