Electrophysiologic study of the biphasic effects of cyclovirobuxine D on arrhythmias / 中国中西医结合杂志
Chinese Journal of Integrated Traditional and Western Medicine
;
(12): 1010-1013, 2004.
Article
in Chinese
| WPRIM
| ID: wpr-284566
ABSTRACT
<p><b>OBJECTIVE</b>To explore the possible mechanism of cyclovirobuxine D (CVB-D) in countering and inducing arrhythmia, by way of studying its electro-physiological effect on ventricular papillary muscles of rats in vitro.</p><p><b>METHODS</b>The transmembrane potential of rat's isolated right ventricular papillary muscles were recorded using conventional glass micro-electrode technique.</p><p><b>RESULTS</b>(1) CVB-D in concentration of 13.3-63.3 micromol/L, showed prolonging effect on the action potential repolarization time, mainly the action potential duration 50 (APD50), APD70 and APD90, in dose-dependent manner, in concentration of 33.3-63.3 micromol/L, it could inhibit the resting potential, action potential amplitude (APA) and maximum depolarization velocity (Vmax) in dose-dependent manner. (2) CVB-D also showed time-dependent effect, the effect initiated 10 min after 20 micromol/L was perfused in ventricular muscle, the APD50, APD70 and APD90 were potentiated gradually along with prolongation of action time and reached the peak at 30-40 min, without any potentiation thereafter. (3) CVB-D could markedly prolong the effective refractory period (ERP) of action potential, increase the ratio of ERP/APD. (4) CVB-D in concentration of 33.3 micromol/L could induce frequent, multifocal spontaneous arrhythmia in some cells when the action time was longer than 45 min.</p><p><b>CONCLUSION</b>CVB-D has the action of anti-ventricular arrhythmia, the mechanism is correlated with the prolongation of APD and ERP of ventricular muscle as well as the increase of ERP/APD ratio, while it also has the effect of inducing arrhythmia, the mechanism might be concerned with excessive prolongation of APD and the inhibition on RP, APA and Vmax.</p>
Full text:
Available
Index:
WPRIM (Western Pacific)
Main subject:
Papillary Muscles
/
Pharmacology
/
Arrhythmias, Cardiac
/
Refractory Period, Electrophysiological
/
In Vitro Techniques
/
Action Potentials
/
Drugs, Chinese Herbal
/
Ventricular Function
/
Rats, Sprague-Dawley
/
Electrophysiologic Techniques, Cardiac
Limits:
Animals
Language:
Chinese
Journal:
Chinese Journal of Integrated Traditional and Western Medicine
Year:
2004
Type:
Article
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