Heterogeneous composition of voltage-dependent K(+) currents in hepatic stellate cells.
OBJECTIVE
Hepatic stellate cells (HSC) are a type of pericyte with varying characteristics according to their location. However, the electrophysiological properties of HSC are not completely understood. Therefore, this study investigated the difference in the voltage-dependent K(+) currents in HSC.


METHODS
The voltage-dependent K(+) currents in rat HSC were evaluated using the whole cell configuration of the patch-clamp technique.


RESULTS
Four different types of voltage-dependent K(+) currents in HSC were identified based on the outward and inward K(+) currents. Type D had the dominant delayed rectifier K(+) current, and type A had the dominant transient outward K(+) current. Type I had an inwardly rectifying K(+) current, whereas the non-type I did not. TEA (5 mM) and 4-AP (2 mM) suppressed the outward K(+) currents differentially in type D and A. Changing the holding potential from -80 to -40 mV reduced the amplitude of the transient outward K(+) currents in type A. The inwardly rectifying K(+) currents either declined markedly or were sustained in type I during the hyperpolarizing step pulses from -120 to -150 mV.


CONCLUSIONS
There are four different configurations of voltage-dependent K(+) currents expressed in cultured HSC. These results are expected to provide information that will help determine the properties of the K(+) currents in HSC as well as the different type HSC populations.
Lee
Dong Hyeon
DH
Division of Biobank for Health Sciences, Korea National Institute of Health, Korea Centers for Disease Control and Prevention, 194 Tongil-ro, Eunpyung-gu, Seoul 122-701, Korea.
Kimm
Kuchan
K
Kim
Hyung-Lae
HL
Han
Bok Ghee
BG
D000818:Animals; D002478:Cells, Cultured; D004553:Electric Conductivity / Q000145:classification; D022781:Hepatocytes / Q000737:chemistry* / Q000145:classification; D017136:Ion Transport; D018408:Patch-Clamp Techniques; D024642:Potassium Channels, Voltage-Gated / Q000502:physiology*; D051381:Rats
D024642:Potassium Channels, Voltage-Gated