March 1, 1998AJP Cell Physiology
Characterization of a transient outward K+ current with inward rectification in canine ventricular myocytes
Key result
Depolarization elicits a Ba2(+)- and K(+o)-sensitive, 4-AP-insensitive transient outward current with inward rectification in canine ventricular myocytes.
Population
Canine ventricular myocytes
Design
Preclinical
Authors
Discussion
Loading...
Member takes
Implication
May modulate canine ventricular excitability; leaves open its presence or role in human myocardium.
Key Points
- To characterize the properties of a transient outward K+ current with inward rectification in canine ventricular myocytes.
- Utilized whole cell patch clamp technique to elicit K+ current in canine ventricular myocytes.
- Investigated the effect of 4-aminopyridine and ryanodine on current response.
- Examined current-voltage relations and inactivation properties of the transient outward K+ current.
- Transient outward K+ current was present at potentials positive to -30 mV.
- Current was abolished by 200 microM Ba2+ or removal of external K+, indicating its dependency on these ions.
- Showed rapid monoexponential recovery from inactivation with a time constant of 13.2 +/- 2.5 ms.
Structured PICO
P
Population
Canine ventricular myocytes
I
Intervention
Whole cell patch clamp technique with application of 5 mM 4-aminopyridine (4-AP), 5 microM ryanodine, 200 microM Ba2+, and varying external K+ concentrations
O
Outcome
Characterization of a transient outward K+ current with inward rectificationsurrogate
The study identifies a novel Ba2+-sensitive, 4-AP-insensitive transient outward K+ current with inward rectification in canine ventricular myocytes that may influence membrane excitability and action potential morphology.
Cite This Study
Li et al. (1998) studied Basic electrophysiology. Depolarization and ion channel blockers (Ba2+, 4-AP) was evaluated on Characterization of transient outward K+ current. Depolarization elicits a Ba2(+)- and K(+o)-sensitive, 4-AP-insensitive transient outward current with inward rectification in canine ventricular myocytes.