The inward rectifier and two levels of the membrane potential in human term placental cells.

Whole-cell variations of patch-clamp techniques were applied to human term placental cells. The inward rectifier K currents were recorded. The current-voltage relationship in some cells crossed the voltage axis at two different potentials. Such cells showed two stable levels of the membrane potential. The current-clamp method could switch the membrane potentials between those two levels. The present results provide evidence that the inward rectifier K conductance could set two changeable levels of the membrane potential in some human term placental cells.