Effects of resibufogenin on membrane responsiveness and afterpotential of human and canine myocardial cells

The membrane responsiveness curve was obtained from measuring the activation potential and Vmax with each intermittent stimulus in every 8 basic stimuli. Ten experiments indicated that RBG shifted the membrane responsiveness curve of canine Purkinje fibers to the right and suggested that RBG decreased the membrane responsiveness and slowed down the impulse conduction and possessed some antiarrhythmic properties. In addition, RBG induced the afterpotentials, including delayed afterdepolarization and oscillatory afterpotential, in canine PF(n=19) and human atrial fibers(n=14).The results suggested that RBG might cause some arrhythmias under centain conditions.