ABSTRACT
Aim To investigate the effect of dipfluzine on hERG potassium currents expressed heterologously in xenopus oocytes.Methods Using Xenopus oocytes expression system,the current amplitude and kinetic characteristics of hERG were measured with the two electrode voltage-clamp technique before and after dipfluzine application.Results Dipfluzine(8 nmol?L-1~5 ?mol?L-1)concentration-dependently inhibited hERG currents;the concentration for half maximal inhibition(IC50)was 98.0 nmol?L-1.Dipfluzine-induced inhibition of hERG currents was voltage dependent at membrane potentials between-10 and 40 mV.Dipfluzine at 1 ?mol?L-1 didn't statistically shifted V1/2 of hERG currents activation.Dipfluzine at 1 ?mol?L-1 significantly decreased the activating time constants and the deactivating time constants,and enhanced hERG currents activation and deactivation.Conclusion Dipfluzine concentration-dependently inhibits hERG currents and modifies kinetic characteristics of hERG activation and deactivation,which may be correlated with its antiarrhythmic effect.