title: Effects of 3,6-dimethylamino-dibenzopyriodonium edetate on action potentials in guinea pig papillary muscles.
abstract: The effects of 3,6-dimethylamino-dibenzopyriodonium edetate (IHC-72) on action potentials (AP) and slow response action potentials of guinea pig papillary muscles were studied with intracellular microelectrodes. IHC-72 12.7, 25.4, and 50.8 mumol.L-1 decreased the maximal upstroke velocity (Vmax), amplitude of action potential (APA), over shot (OS), and resting potential (RP) while prolonged the action potential duration at 30%, 50%, 90%, and 100% repolarization (APD30, APD50, APD90, and APD100). IHC-72 25.4 and 50.8 mumol.L-1 decreased the APA, Vmax, and prolonged APD50 and APD90 under high K+ superfusion. IHC-72 25.4 and 50.8 mumol.L-1 depressed the automaticity, APA, and maximal diastolic potential (MDP) of the slow response action potentials induced by BaCl2. The results indicated that IHC-72 might nonspecifically inhibit the transmembrane movement of Ca2+, Na+, and K+.
authors.affiliation: Department of Pharmacology, Fourth Military Medical University, Xi-an, China.
authors.forename: G J
authors.initials: GJ
authors.lastname: Ji
authors.forename: D H
authors.initials: DH
authors.lastname: Zhao
authors.forename: D Q
authors.initials: DQ
authors.lastname: Liu
authors.forename: B H
authors.initials: BH
authors.lastname: Sheng
mesh_terms: D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D000889:Anti-Arrhythmia Agents / Q000494:pharmacology*; D004492:Edetic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D005260:Female; D006168:Guinea Pigs; D008012:Lidocaine / Q000494:pharmacology; D008297:Male; D009861:Onium Compounds / Q000494:pharmacology*; D010210:Papillary Muscles / Q000187:drug effects* / Q000502:physiology; D014700:Verapamil / Q000494:pharmacology
chemical_list: D000889:Anti-Arrhythmia Agents; D009861:Onium Compounds; C077594:3,6-dimethylaminodibenzopyridonium edetate; D008012:Lidocaine; D004492:Edetic Acid; D014700:Verapamil