A possible interpretation for a wide range of resting membrane potentials in human term placental cells.

Membrane potentials of human term placental cells ranged from 0 mV to -85 mV with two peaks. Two different conductances were recognized. One is the inwardly rectifying K conductance which was responsible for one peak at -75 mV. The other one was the outwardly rectifying conductance which was responsible for another peak at -10 mV. The outwardly rectifying current was suggested to be carried mainly by Cl ions because of the reversal potential and a sensitivity to a Cl channel blocker (DIDS). Membrane potentials in human term placental cells were suggested to range between K and Cl equilibrium potentials.