缬草单萜氧化物对兔单个心室肌细胞L-型钙电流的影响

利用全细胞膜片钳记录技术研究30μg/L和100μg/L缬草单萜氧化物(VMO)对兔单个心室肌细胞L型钙电流(ICaL)和动作电位的影响。结果:30μg/L和100μg/L的VMO使兔心室肌细胞ICaL峰值由6.04±0.59pA/pF分别减至3.99±0.31pA/pF和2.31±0.24pA/pF(n=8,P<0.01);VMO使ICaL的电流电压曲线上移,但不改变其激活电位、电位峰值和反转电位;VMO还使钙电流失活曲线左移。30μg/LVMO可使动作电位时程(APD)明显缩短,APD50和APD90分别缩短了50.3%和29.6%(n=16,P<0.05),而静息电位和动作电位幅值无明显改变。结论:VMO对LCaL具有浓度依赖性阻滞作用。这可能是其对心血管作用的重要机制之一。

Effect of Valerian Extract on L-type Calcium Current and Action Potential in Rabbit Ventricular Myocytes

Whole cell patch clamp technique was used to investigate the effect of valeriana officinalis L extract(VMO) on L-type calcium current(I_ Ca-L) and action potential duration(APD) in rabbit ventricular myocytes . Results: ①30,100μg/L VMO decreased peak I_ Ca-L (I_ Ca-Lmax) from 6.04±0.59 pA/pF to 3.99±0.31 pA/pF and 2.31±0.24 pA/pF( n=8,P<0.01),respectively.VMO upshifted the I-V curves of I_ Ca-L without changes of their active,peak and reverse potentials;②30 μg/L VMO shortened APD_ 50 and APD_ 9052.2% and 35.6% respectively(n=16, P<0.05), but had no significant effect on rest potential and action potential amplitude. Conclusion: VMO blocks I_ Ca-L in a concentration dependent manner and probably inhibits I_ Ca-L in its active state, which may contribute to its cardiovascular effect.