Dauricine suppressed CsCl-induced early afterdepolarizations and triggered arrhythmias in rabbit heart in vivo.
OBJECTIVE
To study the effect of dauricine on CsCl-induced early afterdepolarizations (EAD) and ventricular arrhythmias in rabbits.


METHODS
Monophasic action potentials (MAP) of the left ventricle of the rabbit heart in situ were recorded with MAP recording technique. CsCl 1-2 mmol.kg-1 i.v. was used to induce EAD and ventricular arrhythmias.


RESULTS
CsCl resulted in decrease of MAP amplitude (MAPA, P < 0.05) and prolongation of MAP duration at 90% repolarization (MAPD90, P < 0.01), QRS, and R-R duration (P < 0.05) compared with those before CsCl in the dauricine and control group. CsCl injection induced EAD that appeared within about 30 s and disappeared 5-15 min thereafter. EAD always preceded ventricular arrhythmias including ventricular premature beats and paroxysmal ventricular tachycardia. The EAD amplitude (EADA) in the dauricine group (26% +/- 9% of MAPA) was smaller than that in the control group (52% +/- 5% of MAPA, P < 0.05) and the incidence of arrhythmias in dauricine group (28%) was lower than that in control group (80%, P < 0.05).


CONCLUSIONS
Dauricine exerted an antagonistic effect on EAD and suppressed triggered ventricular arrhythmias by decreasing EADA.
Xia
J S
JS
Institute of Clinical Pharmacology, Tongji Medical University, Wuhan, China. xiajs@hotmail.com
Tu
H
H
Li
Z
Z
Zeng
F D
FD
D000200:Action Potentials / Q000187:drug effects; D000470:Alkaloids; D000818:Animals; D000889:Anti-Arrhythmia Agents / Q000494:pharmacology*; D044182:Benzylisoquinolines; D002586:Cesium; D002712:Chlorides; D005260:Female; D006352:Heart Ventricles / Q000503:physiopathology; D007546:Isoquinolines / Q000494:pharmacology*; D008297:Male; D011817:Rabbits; D017180:Tachycardia, Ventricular / Q000139:chemically induced / Q000503:physiopathology*; D044005:Tetrahydroisoquinolines; D018879:Ventricular Premature Complexes / Q000139:chemically induced / Q000503:physiopathology*
D000470:Alkaloids; D000889:Anti-Arrhythmia Agents; D044182:Benzylisoquinolines; D002712:Chlorides; D007546:Isoquinolines; D044005:Tetrahydroisoquinolines; D002586:Cesium; C035934:dauricine; C028019:cesium chloride