Effects of L-type Calcium Channel Antagonists Verapamil and Diltiazem on fKv1.4ΔN Currents in Xenopus oocytes.

ABSTRACT: The goal of this study was to determine the effects of the L-type calcium channel blockers verapamil and diltiazem on the currents of voltage-gated potassium channel (fKv1.4ΔN), an N-terminal-deleted mutant of the ferret Kv1.4 potassium channel. Measurements were made using a two electrode voltage clamp technique with channels expressed stably in Xenopus oocytes. The fKv1.4ΔN currents displayed slow inactivation, with a half-inactivation potential of -38.38 mV and slow recovery from inactivation (τ = 1.90 seconds at -90 mV). The fKv1.4ΔN currents exhibited state-dependent blockade by both drugs, and the inhibition was frequency-, voltage-, and concentration-dependent, consistent with open channel block. Verapamil and diltiazem blocked fKv1.4ΔN currents with 50% inhibitory concentration (IC

SUBMITTER: Chen H 

PROVIDER: S-EPMC3920693 | biostudies-literature | 2013

REPOSITORIES: biostudies-literature