Dauricine-induced changes in monophasic action potentials and effective refractory period of rabbit left ventricle in situ.
OBJECTIVE
To study the effects of dauricine and sotalol on monophasic action potentials and effective refractory period of the rabbit heart in situ.


METHODS
Monophasic action potentials recording and programmed electrical stimulation techniques.


RESULTS
Iv injection of dauricine 0.5 mg . kg-1 . min-1 for 24 min produced a decrease of the amplitude of monophasic action potentials from (17+/-6) mV to (7.1 +/- 1.5) mV (P < 0.05) and increased the duration of 50 % and 90 % repolarization of monophasic action potentials and effective refractory period from (130 +/- 26), (167 +/- 25), (128 +/- 12) ms to (198 +/- 33), (235 +/- 34), (185 +/- 25) ms (P < 0.05), respectively. Sotalol had the similar effects on monophasic action potentials and effective refractory period to that of dauricine. Dauricine and sotalol did not change the ratio between effective refractory period and the duration of 90 % repolarization.


CONCLUSIONS
Dauricine and sotalol decreased the amplitude of monophasic action potentials and increased the duration of 50 % and 90 % repolarization and effective refractory period.
Xia
Jing-Sheng
JS
Institute of Clinical Pharmacology, Tongji Medical College of Huazhong University of Science and Technology, Wuhan 430030, China. jsxia@sunm.shcnc.ac.cn
Li
Zhen
Z
Dong
Jian-Wen
JW
Tu
Hong
H
Zeng
Fan-Dian
FD
D000200:Action Potentials / Q000187:drug effects*; D000470:Alkaloids; D000818:Animals; D000889:Anti-Arrhythmia Agents / Q000494:pharmacology*; D044182:Benzylisoquinolines; D005260:Female; D006352:Heart Ventricles / Q000187:drug effects; D007546:Isoquinolines / Q000494:pharmacology*; D008297:Male; D011817:Rabbits; D012032:Refractory Period, Electrophysiological / Q000187:drug effects*; D044005:Tetrahydroisoquinolines; D016276:Ventricular Function
D000470:Alkaloids; D000889:Anti-Arrhythmia Agents; D044182:Benzylisoquinolines; D007546:Isoquinolines; D044005:Tetrahydroisoquinolines; C035934:dauricine