ABSTRACT
Objective To investigate the modulation of electrophysiological properties of hyperpolarization-activated cyclic nucleotide-gated channels(HCN) HCN1 and HCN2 by transfecting MinK-related peptide 1(MiRP1) in Chinese hamster ovarian(CHO) cells.Methods CHO cells were co-transfected with plasmid DNA encoding either of the cardiac HCN isoforms(HCN1,HCN2) with MiRP1 to observe the effect of MiRP1 on HCN whole-cell currents.Whole-cell patch clamp technique was used to record the 2 channel currents of the transfected cells.Results MiRP1 significantly increased whole-cell current density of HCN2 [(37.8?4.8) pA/pF(n=11) vs control(25.9?1.7) pA/pF(n=10);at-140 mV,P0.05].Moreover,MiRP1 accelerated the activation kinetic of HCN1 [tau(180.9?8.6) ms vs control(306.1?45.6) ms;at-80 mV,P