Effects of 3,6-dimethamidodibenzopyriodonium citrate on slow inward calcium current in isolated guinea pig ventricular cells.
The effects of 3,6-dimethamidodibenzopyriodonium citrate (I-65) on action potentials and slow inward calcium current (I(si)) were examined on isolated guinea pig ventricular myocardial cells. I-65 (30-100 mumol.L-1) depressed the action potential duration at 20% repolarization (APD20) and, under voltage-clamp conditions, reduced the amplitude of I(si) without changing the I-V relations. I-65 also showed use-dependent effects on I(si). These suggest that I-65 may block I(si) by acting on the inactivated state of Ca channels.
Cui
Y
Y
Department of Pharmacology, 4th Military Medical University, Xi-an, China.
Tan
Y H
YH
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D015220:Calcium Channels / Q000187:drug effects*; D006168:Guinea Pigs; D006321:Heart / Q000187:drug effects*; D008564:Membrane Potentials / Q000187:drug effects; D009206:Myocardium / Q000166:cytology; D009861:Onium Compounds / Q000494:pharmacology*
D015220:Calcium Channels; D009861:Onium Compounds; C056078:3,6-dimethylaminodibenzopyriodonium citrate