Absence of effects of class III antiarrhythmic agents on cloned cardiac K channels.
We investigated the effects of class III antiarrhythmic agents, d-sotalol, E-4031 and MS-551, on the currents of two cloned K channels, Kv1.2 (IKv1.2) and Kv1.4(IKv1.4), by using the Xenopus oocyte expression system. Both IKv1.2 and IKv1.4 were sensitive to 4-aminopyridine and quinidine, but insensitive to tetraethylammonium, d-sotalol, E-4031 and MS-551. The results suggest that some types of structural proteins may be necessary for class III agents to inhibit the cardiac cloned K channels.
Yamagishi
T
T
Department of Pharmacology, Tohoku University School of Medicine, Sendai, Japan.
Ishii
K
K
Taira
N
N
D015761:4-Aminopyridine / Q000494:pharmacology; D000818:Animals; D000889:Anti-Arrhythmia Agents / Q000494:pharmacology*; D003001:Cloning, Molecular; D004594:Electrophysiology; D009206:Myocardium / Q000166:cytology / Q000378:metabolism*; D009865:Oocytes / Q000187:drug effects / Q000378:metabolism; D010880:Piperidines / Q000494:pharmacology; D015221:Potassium Channels / Q000187:drug effects*; D011725:Pyridines / Q000494:pharmacology; D011744:Pyrimidinones / Q000494:pharmacology; D011802:Quinidine / Q000494:pharmacology; D013015:Sotalol / Q000494:pharmacology; D014982:Xenopus laevis
D000889:Anti-Arrhythmia Agents; D010880:Piperidines; D015221:Potassium Channels; D011725:Pyridines; D011744:Pyrimidinones; C063968:E 4031; C076259:nifekalant; D013015:Sotalol; D015761:4-Aminopyridine; D011802:Quinidine