Effects of 3,6-dimethylamino-dibenzopyriodonium edetate on action potentials in guinea pig papillary muscles.
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+.
Ji
G J
GJ
Department of Pharmacology, Fourth Military Medical University, Xi-an, China.
Zhao
D H
DH
Liu
D Q
DQ
Sheng
B H
BH
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
D000889:Anti-Arrhythmia Agents; D009861:Onium Compounds; C077594:3,6-dimethylaminodibenzopyridonium edetate; D008012:Lidocaine; D004492:Edetic Acid; D014700:Verapamil