title: [Electrophysiological effects of guan-fu base A on action potentials of guinea pig ventricular papillary muscles].
abstract: Guan-fu base A (GA), an alkaloid first isolated in China, 50 mg.L-1 decreased the action potential amplitude and the maximal rate of depolarization (Vmax) of guinea pig papillary muscles in vitro. GA shortened the action potential period at 90% repolarization (APD90) without significant effect on the effective refractory period (ERP), resulting in an increased ERP/APD90 ratio. GA 50 mg.L-1 also slowed the conduction speed. The inhibiting effect of GA on Vmax showed frequency- and potential-dependent manners.
authors.affiliation: Department of Medicine, Shanghai Ninth People's Hospital, Shanghai Second Medical University, China.
authors.forename: L M
authors.initials: LM
authors.lastname: Zhou
authors.forename: J M
authors.initials: JM
authors.lastname: Xu
authors.forename: X H
authors.initials: XH
authors.lastname: Chen
authors.forename: Y S
authors.initials: YS
authors.lastname: Xie
mesh_terms: D000200:Action Potentials / Q000187:drug effects; D000470:Alkaloids / Q000494:pharmacology*; D000818:Animals; D000889:Anti-Arrhythmia Agents / Q000494:pharmacology*; D006168:Guinea Pigs; D006576:Heterocyclic Compounds, 4 or More Rings; D066298:In Vitro Techniques; D010210:Papillary Muscles / Q000187:drug effects* / Q000502:physiology; D012032:Refractory Period, Electrophysiological / Q000187:drug effects
chemical_list: D000470:Alkaloids; D000889:Anti-Arrhythmia Agents; D006576:Heterocyclic Compounds, 4 or More Rings; C040615:Guan-fu base A