Effect of Zhigancao Decoction Containing Serum on Transient Outward Potassium Current in Isolated Single Ventricular Myocyte of Rabbits

ObjectiveTo investigate the effect of Zhigancao Decoction (ZD) containing serum on transient outward potassium current (I_ to ) in isolated single ventricular myocyte of rabbits. MethodsSingle rabbit ventricular myocytes were isolated and divided into 6 groups, the normal group, the non-drug-containing serum group, and the ZD groups, they were treated with normal extracellular fluid alone or with ZD containing serum in different concentrations (5%, 10%, 20% and 40%) respectively by perfusion. Whole-cell patch clamp recording technique was used to observe the changes of I_ to . ResultsAfter treated with 5%, 10%, 20% and 40% ZD containing serum, the I_ to was inhibited and its peak value dropped from (16.1±1.4) PA/PF to (13.9± 1.5) PA/PF, (11.8±1.9) PA/PF, (8.3±1.5) PA/PF and (8.2±1.2) PA/PF respectively, and the effect could be eliminated by elution. ConclusionZD containing serum could inhibit the I_ to in isolated ventricular myocytes of rabbits in a concentration-dependent manner, which may be the mechanism of antiarrhythmic action of ZD.