Electrophysiologic properties of cultured human keratinocytes were studied using the patch voltage-clamp technique. Undifferentiated, proliferate keratinocytes grown in low Ca2+ medium had an average resting membrane potential of -24 mV. Voltage-clamp experiments showed that these cells had two membrane ionic currents: a large voltage-independent leak conductance, and a smaller voltage-dependent Cl- current that activated with depolarization. Increasing the extracellular Ca2+ concentration from 0.15 to 2 mM resulted in a doubling of the magnitude of the voltage-gated current and a shift in current activation to more negative potentials. Since levels of extracellular Ca2+ can alter the morphology and differentiation state of keratinocytes, the finding of a Ca2+-activated Cl- current in these cells suggests a role for this conductance in the initiation of differentiation.
|Original language||English (US)|
|Number of pages||8|
|Journal||Journal of Cellular Physiology|
|State||Published - 1990|
ASJC Scopus subject areas
- Clinical Biochemistry
- Cell Biology