Block by a putative antiarrhythmic agent of a calcium-dependent potassium channel in cultured hippocampal neurons
Review articleOpen access
1990/05/04 Full-length article DOI: 10.1016/0304-3940(90)90205-N
Journal: Neuroscience Letters
AbstractThe actions of a new, putative antiarrhythmic drug, KC-8851 on single channel currents in hippocampal CA1 neurons have been studied. A calcium-dependent potassium current IK(Ca) was activated in the cultured neurons when a solution containing 140 mM K+ and 0.2 mM Ca2+ was applied to inside-out patches. Addition of the compound KC-8851, at concentrations between 1–50 μM, resulted in significant, dose-dependent, decreases in the mean open times of the K channel. The onward (blocking) rate constant was determined from a simple channel blockade scheme and was 5 × 107 M−1s−1; this rate constant was not dependent on voltage. Addition of KC-8851 to the solution bath with outside-out patches also caused significant decreases in the mean open times of the IK(Ca) channel consistent with channel blockade by the drug.
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