[Anti-atrial fibrillation effects of cyclovirobuxine-D and its electrophysiological mechanism studied on guinea pig atria].
Cyclovirobuxine-D (CVB-D) was shown to produce significant and dose-dependent protective effects against atrial fibrillation induced by CaCl2-Ach in mice. On atrial fibrillation induced by aconitine, ouabain or adrenaline in isolated guinea pig atria, the effects of CVB-D were similar to those of amiodarone. CVB-D 0.3-100 mumol.L-1 was shown to depress the automaticity of the isolated guinea pig right atria. In isolated left atria, CVB-D 0.3 mumol.L-1 was found to inhibit the abnormal automaticity elicited by adrenaline, to prolong the duration of action potential and effective refractory period and to reduce excitability. At high concentration (30 mumol.L-1), CVB-D was also found to decrease the maximal velocity of depolarization (Vmax) and to elongate the conduction time of initiation. Amiodarone 0.3-30 mumol.L-1 was shown to closely resemble CVB-D in electrophysiology without effect on Vmax.
Wang
Y X
YX
Department of Pharmacology, Fourth Military Medical University, Xian.
Zheng
Y M
YM
Tan
Y H
YH
Sheng
B H
BH
D000157:Aconitine; D000200:Action Potentials / Q000187:drug effects; D000638:Amiodarone / Q000494:pharmacology; D000818:Animals; D000889:Anti-Arrhythmia Agents / Q000494:pharmacology*; D001281:Atrial Fibrillation / Q000139:chemically induced / Q000503:physiopathology*; D002122:Calcium Chloride; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D004594:Electrophysiology; D005260:Female; D006168:Guinea Pigs; D006325:Heart Atria / Q000503:physiopathology; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D012032:Refractory Period, Electrophysiological / Q000187:drug effects
D000889:Anti-Arrhythmia Agents; D004365:Drugs, Chinese Herbal; C032939:cyclovirobuxine D; D002122:Calcium Chloride; D000638:Amiodarone; D000157:Aconitine