Effect of alpha-Allocryptopine on Delayed Afterdepolarizations and Triggered Activities in Mice Cardiomyocytes Treated with Isoproterenol

摘要

Objective. To investigate the effect of alpha-allocryptopine (ALL) on delayed afterdepolarization (DAD) incidence and triggered activity (TA) in mice administered isoproterenol (ISO). Methods. Mouse ventricular myocytes were isolated. And the cellular electrophysiological properties of ventricular myocytes were investigated. Results. We found that the incidences of DADs and TA in mousemyocytes were increased by ISO treatment. In sharp contrast, triggered arrhythmia events were rarely observed in myocytes with 10 mu M ALL treatment. Transient inward current (I-ti) was reduced significantly with ALL treatment, which contributed to DAD-related triggered arrhythmia. Compared to Iso-treated group, the L-type calcium current (I-Ca,I- L) densities were decreased after exposure to ALL, along with slower activation, quicker inactivation, and longer time constant of recovery from in activation kinetics. Conclusion. There is less triggered arrhythmia events in ventricular myocytes treated with ALL. This effect may be associated with the inhibition of I-ti and I-Ca,I- L.