Protective effect of piperine on electrophysiology abnormalities of left atrial myocytes induced by hydrogen peroxide in rabbits.
AIMS
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.


MAIN 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.


KEY FINDINGS
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.


SIGNIFICANCE
These results suggest that piperine effectively protects atrial myocytes from oxidative stress injury in atrial electrophysiology.
['Liu|Yan|Y|', 'Zhang|Yu|Y|', 'Lin|Kun|K|', 'Zhang|De-Xian|DX|', 'Tian|Miao|M|', 'Guo|Hong-Yang|HY|', 'Wang|Yu-Tang|YT|', 'Li|Yang|Y|', 'Shan|Zhao-Liang|ZL|']
D000200:Action Potentials D000470:Alkaloids D000818:Animals D016275:Atrial Function D052117:Benzodioxoles D006325:Heart Atria D006861:Hydrogen Peroxide D008564:Membrane Potentials D008839:Microelectrodes D032383:Myocytes, Cardiac D018384:Oxidative Stress D010880:Piperidines D053284:Polyunsaturated Alkamides D011817:Rabbits
Piperine Atrial myocytes Hydrogen peroxide Action potential