Dihydromyricetin Inhibits hKv1.5 Channel Expressed in HEK 293 Cells

【摘要】：4、血液和循环生理学Background:Dihydromyricetin(Dmy)is a derivative of myricetin and a flavonoids.The previous studies reported that myricetin(Myr)had antiarrhythmic effect that Myr can slow down the heart rate.In addition,there is a relationship between h Kv1.5 channel and antiarrhythmic.The present study was designed to investigate the effect of Dmy on h Kv1.5 channel expressed in HEK293 cells using a whole-cell patch voltage-clamp technique.Methods:h Kv1.5 was expressed in HEK293 cells with transfection by Lipofectamine and currents were recorded under whole-cell configuration with patch clamp technique.Dmy was added into the bath solution to obtain the final concentration.Results:Dmy reduced the current density of Ikur in a dose-dependent manner with the half inhabitation concentration(IC50)of 3.69μM and 10μM Dmy reduced the current density of IKur from 116.59±14.30(p A/p F)to 57.23±9.57(p A/p F)(n=14,P0.001)after Dmy was treated by 20 min.The Ikur was reduced under the effect of Dmy from 5 min to 20 min.The current density with the effect of Dmy was normalized as that in 5 minutes,the normalized current were 0.89±0.02 in 10 min(n=30,P0.001,vs 5min),0.82±0.03 in 15min(n=30,P0.001,vs 10 min),0.77±0.03 in 20 min(n=18,P0.001,vs 15min).Normalizing the current density with the Ikur at 1 Hz.Normalized Ikur was 0.92±0.01 at 3 Hz(n=36,P0.001,vs.1 Hz),0.86±0.01 at 4 Hz(n=36,P0.001,vs.3 Hz).Conclusions:Dmy inhibited Ikur expressed of HEK 293 cell with dose-,time-and frequency-dependence.These results may contribute to the effect Dmy on slowing down heart rate.