Effect of carboxymethyl chitosan on ATP-sensitive K~+ currents in single ventricular myocyte of rat / 中国海洋药物

ABSTRACT

Objective To investigate the effect of carboxymethyl chitosan on ATP-sensitive K+ currents(IKATP) in single ventricular myocyte of rat.Methods Single ventricular myocyte of rat was isolated with enzymatic dissociation technique.Whole-cell patch clamp technique was used.The stimulating protocol was:holding potential-40 mV,command potential-100 mV to +50 mV,step potential + 10 mV,duration 200 ms,stimulating interval 6 s.Results Carboxymethyl chitosan inhibited the ATP-sensitive K+ channel(KATP channel) in a dose-dependent manner.When holding potential was-60 mV and stimulating potential was + 50 mV,carboxymethyl chitosan(0.1%,0.2%,0.3%) decreased the amplitude values of IKATP to 66.1%?9.9%,50.3%?13.3%and 39.8%?9.5%(n=7)of control,respectively.The changes of IKATP under other command potentials were consistent with this.Conclusion Carboxymethyl chitosan inhibits KATP channel in single ventricular myocyte of rat in a dose-dependent manner,and may be one of the mechanisms of antiarrhythmia.