Two types of voltage-dependent outward potassium currents in smooth muscle cells of rabbit basilar artery
The Korean Journal of Physiology and Pharmacology
; : 169-183, 1997.
Article
in English
| WPRIM (Western Pacific)
| ID: wpr-728635
Responsible library:
WPRO
ABSTRACT
We have investigated the two types of voltage-dependent outward potassium (K) currents, i.e. delayed rectifier K current (I-K(V)) and 'A-like' transient outward K current (I-to) with patch-clamp technique in single smooth muscle cells (SMCs) isolated from rabbit basilar artery, and investigated the characteristics of them. The time-courses of activation were well fitted by exponential function raised to second power (n-2) in I-K(v) and fourth power (n-4) in I-to. The activation, inactivation and recovery time courses of I-to were much faster than that of I-K(V). The steady-state activation and inactivation of I-K(V) was at the more hyperpolarized range than that of I-to contrary to the reports in other vascular SMCs. Tetraethylammonium chloride (TEA; 10 mM) markedly inhibited I-K(V) but little affected 1-to. 4-Aminopyridine (4-AP) had similar inhibitory potency on both currents. While a low concentration of Cd-2+ (0.5 mM) shifted the current-voltage relationship of I-to to the positive direction without change of maximum conductance, Cd-2+ did not cause any appreciable change for I-K(V).
Full text:
Available
Database:
WPRIM (Western Pacific)
Main subject:
Potassium
/
Basilar Artery
/
4-Aminopyridine
/
Patch-Clamp Techniques
/
Tetraethylammonium
/
Myocytes, Smooth Muscle
/
Muscle, Smooth
Language:
English
Journal:
The Korean Journal of Physiology and Pharmacology
Year:
1997
Document type:
Article