Inwardly Rectifying K+ Currents in Gastric Myocytes of Guinea-pig
The Korean Journal of Physiology and Pharmacology
;
: 47-56, 2002.
Article
in English
| WPRIM
| ID: wpr-728770
ABSTRACT
To identify the presence of inwardly rectifying K+ channels and its characteristics, membrane currents were measured using a whole-cell patch clamp from isolated gastric myocytes of guinea-pig. Change of external K+ concentration from 5 to 90 mM induced an inward current at a holding potential of 80 mV. The high K+-induced inward current was blocked by Ba2+ and Cs+, but not by glibenclamide. With 90 mM K+ in bath, the Ba2+- and Cs+-sensitive currents showed strong inward rectification. Ten mM TEA weakly blocked the inward current only at potentials more negative than 50 mV. With 90 mM K+ in bath, hyperpolarizing step pulses from 10 mV induced inward currents, which were inactivated at potentials more negative than 70 mV. Reduction of external K+ to 60 mM decreased the amplitudes of the currents and shifted the reversal potential to more negative potential. The inactivation of inward K+ current at negative clamp voltage was not affected by removing external Na . These results suggest that the inwardly rectifying K+ channels may exist in gastric smooth muscle.
Full text:
Available
Index:
WPRIM (Western Pacific)
Main subject:
Tea
/
Baths
/
Glyburide
/
Muscle Cells
/
Membranes
/
Muscle, Smooth
Type of study:
Prognostic study
Language:
English
Journal:
The Korean Journal of Physiology and Pharmacology
Year:
2002
Type:
Article
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