Effect of guan-fu base A on action potential of canine Purkinje Fibers

Guan-fu base A is a new alkaloid isolated from the tuber of Aconitum coreanum in our institute. The following parameters were obtained by using a micro-computer system for automatic analysis of canine Purkinje fibers in vitro. After treating with guan-fu base A (100 microg/mL) for 20 min, the amplitude and Vmax of action potentials were decreased from 110+/-6 to 96+/-3 mV and 341+/-68 to 194+/-94 V/s, respectively. The duration of action potential at 100% of repolarization (APD100) and effective refractory period were lengthened from 341+/-28 to 371+/-31 ms and 270+/-24 to 346+/-47 ms, respectively. The ratio of ERP/APD100 increased. It is suggested that guan-fu base A possessed the electrophysiological properties of anti-arrhythmic drugs.