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ELECTROPHYSIOLOGICAL EFFECTS OF CHANGROLIN, AN ANTIARRHYTHMIC AGENT DERIVED FROM DICHROA FEBRIFUGA , ON GUINEA‐PIG AND RABBIT HEART CELLS
Author(s) -
Lu LingLing,
Habuchi Yoshizumi,
Tanaka Hideo,
Morikawat Junichiro
Publication year - 1995
Publication title -
clinical and experimental pharmacology and physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 103
eISSN - 1440-1681
pISSN - 0305-1870
DOI - 10.1111/j.1440-1681.1995.tb02011.x
Subject(s) - guinea pig , rabbit (cipher) , electrophysiology , pharmacology , biology , medicine , statistics , mathematics
SUMMARY 1. The electrophysiological effects of changrolin (CRL), a Chinese antiarrhythmic drug derived from a traditional anti‐malarial plant, were examined using the whole‐cell patch‐clamp method on single cells isolated from guinea‐pig and rabbit hearts. 2. At a clinically relevant concentration of 50μmol/L changrolin inhibited Ic a . by 19.3 ± 6.0% and 17.3 ± 2.6% in guinea‐pig and rabbit ventricular cells, respectively. The voltage‐dependent channel availability curve was not affected. The CRL effect was enhanced to a small extent during a repetitive stimulation at 2 Hz. 3. In a was resistant to CRL and the channel availability curve was also unaffected. A small use‐dependent inhibition was observed only when the In a was elicited at 5 Hz in the presence of 300 μmol/L CRL. 4. At 50 μmol/L, CRL did not affect the time‐independent inward rectifier and the delayed rectifier K + currents (Iki and Ik, respectively), but inhibited the transient outward current (Ito) by 17.7 ± 2.4%. Changrolin significantly shortened the action potential duration in both guinea‐pig and rabbit ventricular cells. 5. In conclusion, CRL inhibits Ic a and Ito but has little effect on In a .