Effects of solution of dry powder of ShenSongYangXin capsule on sodium current and L-type calcium current in ventricular myocytes: experiment with guinea pig
Li, N.; Huo, Y.-p.; Ma, K.-j.; Sun, Q.; Pu, J.-l.
Zhonghua Yi Xue Za Zhi 87(14): 995-998
2007
ISSN/ISBN: 0376-2491 PMID: 17650428 Document Number: 606586
To investigate the effects of dry powder of ShenSongYangXin capsule on sodium current (I(Na)) and L-type calcium current (I(Ca, L)) in ventricular myocytes. Ventricular myocytes were isolated from guinea pig. Solution of the dry powder of ShenSongYangXin capsule of the concentrations of 1%, 0.5%, and 0.25% was added into the suspension of the myocytes. Whole cell patch-clamp technique was used to detect the I(Na) and I(Ca, L) in the ventricular myocytes. ShenSongYangXin decreased the peak I(Na) from 27.2 +/- 5.4 (pA/pF) to 14.9 +/- 2.8 (pA/pF), with a decrease rate of 44.8% +/- 7.7% (n = 5, P < 0.05). The solution of dry powder of ShenSongYangXin of the concentrations of 1%, 0.5%, and 0.25% decreased the peak L-type calcium channel current (I(ca, L)) significantly in a concentration dependent manner with the reduction rates of 50.7% +/- 5.6%, 44.8% +/- 6.5%, and 19.2% +/- 1.1% respectively (n = 5, all P < 0.05). ShenSongYangXin shifted up both the I approximately 1V curve of I(Na) and that of I(Ca, L), while their active, peak and reverse potentials didn't change. ShenSongYangXin blocks both I(Na) and I(Ca, L), which may contributes to some of its antiarrhythmic effect.