Effects of Propofol in Voltage-dependent Potassium Channels in Human Neurl Stem Cells

ABSTRACT

BACKGROUND: Human neural stem cells have at least two types of voltage-dependent potassium channels including inward and outward rectifying potassium channels. Data for the effects of propofol, intravenous anesthetics, on human neural potassium channels are limited. We have examined the effects of propofol on voltage-dependent potassium channels in human neural stem cells. METHODS: Voltage-dependent potassium currents were measured in cultured human neural stem cells using the whole cell patch-clamp technique before and after application of 0.1 mM propofol. Inward and outward rectifying potassium currents were elicited by hyperpolarizing and depolarizing step pulses from -60 mV holding potential, respectively. RESULTS: Propofol was found to reversibly block the outward rectifying potassium current (p<0.05), while the anesthetics did not alter the characteristics of inward rectifying potassium current. The blocking effect of propofol on outward rectifying current was voltage-dependent and enhanced at depolarization potentials above +30 mV (p<0.05). Propofol also decreased the slope conductance of outward potassium current (p<0.05). CoNCLUSION: These results show that propofol may strongly affect the outward potassium channels in human neural stem cells and also suggest a need for investigation into the effect of propofol on the functional regulation of human neural stem cells.