title: Protective effect of piperine on electrophysiology abnormalities of left atrial myocytes induced by hydrogen peroxide in rabbits.
abstract: OBJECTIVE
  Piperine had protective effects on oxidative stress damage of ventricular myocytes by hydrogen peroxide (H2O2). In this study we aimed to explore the protective effect of piperine on abnormalities of the cardiac action potential (AP) and several ion currents induced by hydrogen peroxide (H2O2) in single rabbit left atrial myocyte.
  
  
  METHODS
  Conventional microelectrodes were used to record action potential duration (APD), resting membrane potential (RMP) and some ion currents (ICa,L,Ito,IK1 and Ikur,ect.), before and after H2O2 administration with or without piperine.
  
  
  RESULTS
  The piperine (7 μmol/L) had no significant effect on APD, ICa,L,Ito,IK1 and Ikur and their channel dynamics. In the presence of 50 μmol/L H2O2, APD50 and APD90 shortened (P<0.01), amplitude of RMP decreased (P<0.05), the peak of ICa,L reduced significantly (P<0.05). Piperine (7 μmol/L) significantly alleviated the inhibiting effect of H2O2 on APD and ICa,L (P<0.01) and protected the changes of ICa,L dynamics induced by H2O2. The peak current of Ito was reduced significantly (P<0.05); Piperine (7 μmol/L) significantly alleviated the inhibiting effect of H2O2 on Ito (P<0.01). In addition, piperine protected the changes of Ito dynamics induced by H2O2. The peak current of IK1 and IKUr was significantly reduced (P<0.05); Piperine (7 μmol/L) alleviated the inhibiting effect of H2O2 on IK1 and IKUr significantly (P<0.01). In addition, piperine protected the changes of IKUr dynamics induced by H2O2.
  
  
  CONCLUSIONS
  These results suggest that piperine effectively protects atrial myocytes from oxidative stress injury in atrial electrophysiology.
authors.affiliation: Department of Cardiology, Chinese PLA General Hospital, Beijing 100853, China; Department of Cardiology, Liao He Hospital, Liao Ning 111000, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Cardiology, Chinese PLA General Hospital, Beijing 100853, China; Nankai University School of Medicine, Nankai University, Tianjin 300071, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Cardiology, Chinese PLA General Hospital, Beijing 100853, China.
authors.forename: Kun
authors.initials: K
authors.lastname: Lin
authors.affiliation: Department of Cardiology, Chinese PLA General Hospital, Beijing 100853, China; Nankai University School of Medicine, Nankai University, Tianjin 300071, China.
authors.forename: De-Xian
authors.initials: DX
authors.lastname: Zhang
authors.affiliation: Department of Cardiology, the First Affiliated Hospital of Chinese PLA General Hospital, Beijing 100048, China.
authors.forename: Miao
authors.initials: M
authors.lastname: Tian
authors.affiliation: Department of Cardiology, Chinese PLA General Hospital, Beijing 100853, China.
authors.forename: Hong-Yang
authors.initials: HY
authors.lastname: Guo
authors.affiliation: Department of Geriatric Cardiology, Chinese PLA General Hospital, Beijing 100853, China.
authors.forename: Yu-Tang
authors.initials: YT
authors.lastname: Wang
authors.affiliation: Institute of Geriatric Cardiology, Chinese PLA General Hospital, Beijing 100853, China. Electronic address: liyangbsh@163.com.
authors.forename: Yang
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Cardiology, Chinese PLA General Hospital, Beijing 100853, China. Electronic address: shanzl301@sina.com.
authors.forename: Zhao-Liang
authors.initials: ZL
authors.lastname: Shan
mesh_terms: D000200:Action Potentials / Q000187:drug effects* / Q000502:physiology; D000470:Alkaloids / Q000494:pharmacology*; D000818:Animals; D016275:Atrial Function / Q000187:drug effects / Q000502:physiology; D052117:Benzodioxoles / Q000494:pharmacology*; D006325:Heart Atria / Q000166:cytology / Q000187:drug effects; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D008839:Microelectrodes; D032383:Myocytes, Cardiac / Q000187:drug effects* / Q000502:physiology; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology; D010880:Piperidines / Q000494:pharmacology*; D053284:Polyunsaturated Alkamides / Q000494:pharmacology*; D011817:Rabbits
chemical_list: D000470:Alkaloids; D052117:Benzodioxoles; D010880:Piperidines; D053284:Polyunsaturated Alkamides; D006861:Hydrogen Peroxide; C008922:piperine
keywords: Action potential; Atrial myocytes; Hydrogen peroxide; Piperine