title: Effects of 7-bromoethoxybenzene-tetrahydropalmatine on voltage-dependent currents in guinea pig ventricular myocytes.
abstract: OBJECTIVE
  To study the anti-arrhythmic mechanism of 7-bromoethoxybenzene-tetrahydropalmatine (EBP).
  
  
  METHODS
  Whole-cell current and voltage clamp on isolated guinea pig ventricular cells.
  
  
  RESULTS
  EBP 30 mumol.L-1 prolonged APD90 from 430 +/- 47 ms to 514 +/- 61 ms (n = 5, P < 0.05) without effects on the action potential amplitude and resting potential. Delayed outward K+ current and its tail current were blocked by EBP in a concentration-dependent fashion, while EBP did not change the amplitudes of the sodium current, the L type calcium current, and the inwardly rectifying potassium current.
  
  
  CONCLUSIONS
  The mechanism of anti-arrhythmic action of EBP was to prolong the APD through inhibiting the delayed rectified potassium current.
authors.affiliation: Institute of Biophysics & Biochemistry, Huazhong University of Science & Technology, Wuhan 430074, China.
authors.forename: X W
authors.initials: XW
authors.lastname: Niu
authors.forename: T
authors.initials: T
authors.lastname: Zeng
authors.forename: A L
authors.initials: AL
authors.lastname: Qu
authors.forename: H G
authors.initials: HG
authors.lastname: Kang
authors.forename: S P
authors.initials: SP
authors.lastname: Dai
authors.forename: W X
authors.initials: WX
authors.lastname: Yao
authors.forename: M X
authors.initials: MX
authors.lastname: Jiang
mesh_terms: D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D000889:Anti-Arrhythmia Agents / Q000494:pharmacology*; D001600:Berberine Alkaloids / Q000494:pharmacology*; D002478:Cells, Cultured; D006168:Guinea Pigs; D006352:Heart Ventricles; D008564:Membrane Potentials / Q000187:drug effects; D009206:Myocardium / Q000166:cytology*; D018408:Patch-Clamp Techniques; D015221:Potassium Channels / Q000187:drug effects
chemical_list: D000889:Anti-Arrhythmia Agents; D001600:Berberine Alkaloids; D015221:Potassium Channels; C061390:7-(bromoethoxyphenyl)tetrahydropalmatine