title: The cellular electrophysiologic effect of a new amiodarone like antiarrhythmic drug GYKI 16638 in undiseased human ventricular muscle: comparison with sotalol and mexiletine.
abstract: The cellular electrophysiologic effect of GYKI 16638, a new antiarrhythmic compound was studied and compared with that of sotalol and mexiletine in undiseased human right ventricular muscle preparation by applying the conventional microelectrode technique. GYKI 16638 (5 microM), at stimulation cycle length of 1000 ms, lengthened action potential duration (APD(90)) from 338.9 +/- 28.6 ms to 385.4 +/- 24 ms (n = 9, p > 0.05). This APD lengthening effect, unlike that of sotalol (30 microM), was rate-independent. GYKI 16638, contrary to sotalol and like mexiletine (10 microM), exerted a use-dependent depression of the maximal rate of depolarization (V(max)) which amounted to 36.4 +/- 11.7% at cycle length of 400 ms (n = 5, p < 0.05) and was characterised with an offset kinetical time constant of 298.6 +/- 70.2 ms. It was concluded that GYKI 16638 in human ventricular muscle shows combined Class IB and Class III antiarrhythmic properties, resembling the electrophysiological manifestation seen after chronic amiodarone treatment.
authors.affiliation: Department of Pharmacology & Pharmacotherapy, Albert Szent-Györgyi Medical and Pharmaceutical Center, University of Szeged, Szeged, Hungary.
authors.forename: M
authors.initials: M
authors.lastname: Opincariu
authors.forename: A
authors.initials: A
authors.lastname: Varró
authors.forename: N
authors.initials: N
authors.lastname: Iost
authors.forename: L
authors.initials: L
authors.lastname: Virág
authors.forename: O
authors.initials: O
authors.lastname: Hála
authors.forename: J
authors.initials: J
authors.lastname: Szolnoki
authors.forename: J
authors.initials: J
authors.lastname: Szécsi
authors.forename: G
authors.initials: G
authors.lastname: Bogáts
authors.forename: P
authors.initials: P
authors.lastname: Szenohradszky
authors.forename: P
authors.initials: P
authors.lastname: Mátyus
authors.forename: J Gy
authors.initials: JG
authors.lastname: Papp
mesh_terms: D000200:Action Potentials / Q000187:drug effects; D000328:Adult; D000638:Amiodarone / Q000494:pharmacology*; D000889:Anti-Arrhythmia Agents / Q000494:pharmacology*; D004558:Electric Stimulation; D004594:Electrophysiology; D005260:Female; D006321:Heart / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D066298:In Vitro Techniques; D007700:Kinetics; D008297:Male; D008801:Mexiletine / Q000494:pharmacology*; D010210:Papillary Muscles / Q000187:drug effects; D010627:Phenethylamines / Q000494:pharmacology*; D013015:Sotalol / Q000494:pharmacology*; D013449:Sulfonamides / Q000494:pharmacology*; D016278:Ventricular Function, Right / Q000187:drug effects
chemical_list: D000889:Anti-Arrhythmia Agents; D010627:Phenethylamines; D013449:Sulfonamides; D008801:Mexiletine; C420122:GYKI 16638; D013015:Sotalol; D000638:Amiodarone