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Planta Med 2011; 77(13): 1477-1481
DOI: 10.1055/s-0030-1270742
Biological and Pharmacological Activity
Original Papers
© Georg Thieme Verlag KG Stuttgart · New York

Protective Effects of Isorhynchophylline on Cardiac Arrhythmias in Rats and Guinea Pigs

Runtao Gan1 , Guo Dong1 , Jiangbo Yu1 , Xu Wang1 , Songbin Fu2 , Shusen Yang1
  • 1Department of Cardiology, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang Province, PR China
  • 2Department of Genetics, Basic Medical College of Harbin Medical University, Harbin, Heilongjiang Province, PR China
Further Information

Publication History

received Nov. 28, 2010 revised January 18, 2011

accepted January 19, 2011

Publication Date:
03 February 2011 (online)

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Abstract

As one important constituent extracted from a traditional Chinese medicine, Uncaria rhynchophylla Miq Jacks, isorhynchophylline has been used to treat hypertension, epilepsy, headache, and other illnesses. Whether isorhynchophylline protects hearts against cardiac arrhythmias is still incompletely investigated. This study was therefore aimed to examine the preventive effects of isorhynchophylline on heart arrhythmias in guinea pigs and rats and then explore their electrophysiological mechanisms. In vivo, ouabain and calcium chloride were used to establish experimental arrhythmic models in guinea pigs and rats. In vitro, the whole-cell patch-lamp technique was used to study the effect of isorhynchophylline on action potential duration and calcium channels in acutely isolated guinea pig and rat cardiomyocytes. The dose of ouabain required to induce cardiac arrhythmias was much larger in guinea pigs administered with isorhynchophylline. Additionally, the onset time of cardiac arrhythmias induced by calcium chloride was prolonged, and the duration was shortened in rats pretreated with isorhynchophylline. The further study showed that isorhynchophylline could significantly decrease action potential duration and inhibit calcium currents in isolated guinea pig and rat cardiomyocytes in a dose-dependent manner. In summary, isorhynchophylline played a remarkably preventive role in cardiac arrhythmias through the inhibition of calcium currents in rats and guinea pigs.

Key words

Uncaria rhynchophylla - Rubiaceae - isorhynchophylline - arrhythmias - calcium channel

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Prof. Shusen Yang, PhD

Department of Cardiology
The First Affiliated Hospital of Harbin Medical University

Youzheng Street 23#

Harbin 150001

PR China

Phone: +86 4 51 86 65 04 82

Fax: +86 4 51 86 65 04 82

Email: Ganrt@126.com