TY - JOUR
T1 - Characteristics of potassium and calcium currents of hepatic stellate cells (Ito) in rat
AU - Lee, Keon Il
AU - Kong, In Deok
AU - Baik, Soon Koo
AU - Kim, Hyun Soo
AU - Lee, Dong Ki
AU - Kwon, Sang Ok
AU - Chun, Boe Gwun
PY - 2004/8/31
Y1 - 2004/8/31
N2 - Hepatic stellate cells (HSCs) are known to play a role in the pathogenesis of the increased intrahepatic vascular resistance found in chronic liver diseases. The aim of this study was to evaluate the K+ and Ca2+ currents in cultured HSCs from rat liver, through the patch-clamp technique. Most cells were positive for desmin immunostain after isolation and in α-smooth muscle actin immunostain after 10 - 14 days of culturing. Outward and inward rectifying K+ currents were confirmed. Two different types of K+ currents were distinguished: one with the inward rectifying current and the other without. The outward K+ currents consisted of at least four components: tetraethylammonium (TEA -sensitive current, 4-aminopyridine (4-AP)-sensitive current, pimozide-sensitive current and three blocker-resistant current. The peaks of the outward K+ currents evoked by a depolarizing pulse were decreased to 32.0 ± 3.0, 62.8 ± 3.7 and 32.8 ± 3.5% by 5 mM TEA, 2 mM 4-AP and 15 μM pimozide, respectively. Moreover, the combined application of three blockers caused 86.6 ± 4.8% suppression. The inward currents evoked hyperpolarizing pulses were inwardly rectifying and almost blocked by Ba2+. Elevation of external K+ increased the inward current amplitude and positively shifted its reversal potential. Voltage-dependent Ca2+ currents which were completely abolished by Cd2+ and nimodipine were detected in 14 day cultured HSCs. In this study, the cultured HSCs were found to express outward K+ current composed of multiple pharmacological components, Ba2+-sensitive inward rectifying K+ current and L-type Ca2+ current.
AB - Hepatic stellate cells (HSCs) are known to play a role in the pathogenesis of the increased intrahepatic vascular resistance found in chronic liver diseases. The aim of this study was to evaluate the K+ and Ca2+ currents in cultured HSCs from rat liver, through the patch-clamp technique. Most cells were positive for desmin immunostain after isolation and in α-smooth muscle actin immunostain after 10 - 14 days of culturing. Outward and inward rectifying K+ currents were confirmed. Two different types of K+ currents were distinguished: one with the inward rectifying current and the other without. The outward K+ currents consisted of at least four components: tetraethylammonium (TEA -sensitive current, 4-aminopyridine (4-AP)-sensitive current, pimozide-sensitive current and three blocker-resistant current. The peaks of the outward K+ currents evoked by a depolarizing pulse were decreased to 32.0 ± 3.0, 62.8 ± 3.7 and 32.8 ± 3.5% by 5 mM TEA, 2 mM 4-AP and 15 μM pimozide, respectively. Moreover, the combined application of three blockers caused 86.6 ± 4.8% suppression. The inward currents evoked hyperpolarizing pulses were inwardly rectifying and almost blocked by Ba2+. Elevation of external K+ increased the inward current amplitude and positively shifted its reversal potential. Voltage-dependent Ca2+ currents which were completely abolished by Cd2+ and nimodipine were detected in 14 day cultured HSCs. In this study, the cultured HSCs were found to express outward K+ current composed of multiple pharmacological components, Ba2+-sensitive inward rectifying K+ current and L-type Ca2+ current.
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U2 - 10.3349/ymj.2004.45.4.649
DO - 10.3349/ymj.2004.45.4.649
M3 - Article
C2 - 15344206
AN - SCOPUS:4644349694
VL - 45
SP - 649
EP - 660
JO - Yonsei Medical Journal
JF - Yonsei Medical Journal
SN - 0513-5796
IS - 4
ER -