Effects of sodium ferulate on the ultrarapid delayed rectifier K~+ current in human atrial myocytes

Objective:To study the effects of sodium ferulate on the ultrarapid delayed rectifier K+ current(IKur) in human atrial myocytes. Methods:Human atrial myocytes were isolated by enzyme dispersion method. IKur in human atrial myocytes were recorded by using the whole cell patch clamp. The changes of IKur were compared in the absence and the presence of sodium ferulate. Results:There was no effect of 0.4 g/L sodium ferulate on I-V relation of IKur. However, 0.4 g/L sodium ferulate inhibited IKur to some degrees at each test pulse. The current densities of IKur at +60 mV decreased from 4.997 ± 0.35 PA/PF to 3.331 ± 0.26 PA/PF(n = 6, P < 0.05). The inhibitory effect was concentration-dependent. IC50 was(0.41±0.03)g/L and the Hill coefficient was 0.95±0.05. Conclusion:Sodium ferulate as a potassium channel blocker can inhibit IKur in human atrial myocytes effectively.