title: [Comparison of the anti-arrhythmic effects of matrine and berbamine with amiodarone and RP58866].
abstract: OBJECTIVE
  To clarify mechanisms that the antiarrhythmic effects of matrine and berbamine are weaker than those of amiodarone and RP58866.
  
  
  METHODS
  Experimental arrhythmic models were induced by aconitine, coronary artery ligation and electric stimulation in rats and rabbits. Whole-cell patch-clamp techniques were used to record IK1, IKr, IKs and Ito.
  
  
  RESULTS
  Matrine and berbamine significantly increased the dose of aconitine for induction of ventricular premature and ventricular tachycardia in rats, decreased the number of arrhythmias induced by coronary artery ligation in rats and increased ventricular fibrillation threshold (VFT) induced by electric stimulation in rabbits, but the anti-arrhythmic potency of matrine and berbamine was lower than that of amiodarone and RP58866. The inhibitory actions of matrine and berbamine on IK1, IKr, IKs, Ito were lower than those of amiodarone and RP58866. The IC50 of matrine for IK1, IKr, IKs, Ito were (46 +/- 3), (32.9 +/- 1.2), (37 +/- 8) and (7.6 +/- 0.5) mol x L(-1), respectively. The IC50 of amiodarone for IK1, IKr, IKs, Ito were (21 +/- 5) , (3.7 +/- 0.7), (5.9 +/- 0.9) and (5.9 +/- 0.6) mol x L(-1), respectively.
  
  
  CONCLUSIONS
  The inhibitory actions of matrine and berbamine on IK1, IKr, IKs, Ito were lower than those of amiodarone and RP58866, which might be the reason that the antiarrhythmic effects of matrine and berbamine were weaker than those of amiodarone and RP58866.
authors.affiliation: Department of Pharmacology, Harbin Medical University, Bio-Pharmaceutical Key Laboratory of Heilongjiang Province-Incubator of State Key Laboratory, Harbin 150086, China.
authors.forename: Chao-qian
authors.initials: CQ
authors.lastname: Xu
authors.forename: De-li
authors.initials: DL
authors.lastname: Dong
authors.forename: Zhi-min
authors.initials: ZM
authors.lastname: Du
authors.forename: Qing-wen
authors.initials: QW
authors.lastname: Chen
authors.forename: Dong-mei
authors.initials: DM
authors.lastname: Gong
authors.forename: Bao-feng
authors.initials: BF
authors.lastname: Yang
mesh_terms: D000157:Aconitine; D000470:Alkaloids / Q000494:pharmacology*; D000638:Amiodarone / Q000494:pharmacology*; D000818:Animals; D000889:Anti-Arrhythmia Agents / Q000494:pharmacology*; D001145:Arrhythmias, Cardiac / Q000139:chemically induced / Q000503:physiopathology / Q000517:prevention & control; D044182:Benzylisoquinolines / Q000494:pharmacology*; D002839:Chromans / Q000494:pharmacology*; D004285:Dogs; D005260:Female; D006168:Guinea Pigs; D008297:Male; D010880:Piperidines / Q000494:pharmacology*; D015221:Potassium Channels / Q000187:drug effects; D011807:Quinolizines; D011817:Rabbits; D051381:Rats; D000093842:Matrines
chemical_list: D000470:Alkaloids; D000889:Anti-Arrhythmia Agents; D044182:Benzylisoquinolines; D002839:Chromans; D010880:Piperidines; D015221:Potassium Channels; D011807:Quinolizines; C063899:terikalant; D000638:Amiodarone; C027870:berbamine; D000157:Aconitine; D000093842:Matrines