The effects of paeoniflorin monomer on cardiac potassium currents
WANG Rong-rong, WANG Ke, LI Ning, RAN Yu-qin, PU Jie-lin,Pathology and Physiology Research Center, Cardiovascular Institute and Fu Wai Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100037, China
Objective The present study was to determine the effects of paeoniflorin on inward rectifier potassium current (IK1), transient outward potassium current (Ito), and delayed rectifier current (IKs and IKr). Methods Whole-cell patch-clamp technique was used to record ion channel currents. IK1 and Ito were studied in rat ventricular myocytes; and IKs and IKr were investigated in transfected HEK293 cells. Results 100μmol/L paeoniflorin inhibited the IK1 by 30.13% at the test potential of -100mV (from (-25.26±8.21) pA/pF to (-17.65±6.52) pA/pF, n=6, P0.05) without effects on the reversal potential and the rectification property. Moreover, 100μmol/L paeoniflorin had no effects on Ito, IKs or IKr channels. Conclusions The study demonstrated that paeoniflorin blocked IK1 without affecting Ito,IKs, or IKr.