灯盏花素对豚鼠心室肌细胞I_(Ca)的影响

Effects of breviscapine on slow inward calium current in single ventricular cells of guinea pigs

目的观察灯盏花素对豚鼠心室肌单细胞钙离子电流(ICa)的影响。方法采用全细胞膜片钳制技术。结果灯盏花素能使豚鼠心室肌细胞ICa减小,连续刺激后,对ICa的抑制作用加强,与给药前比较,差异显著(P<0.01);此作用具有明显的电压依赖性,在峰电流电压下作用最明显,而对其反转电位无明显影响;灯盏花素对ICa的作用随质量浓度升高而加强,在指令电压0 mV时,5、10和20 mg.L-1灯盏花素使ICa分别减小5.4%、22.9%和45.0%(P<0.01),且可以恢复;在不同的刺激频率下,灯盏花素均可使ICa减小,尤其对高频率刺激细胞产生的ICa作用更明显(P<0.05)。结论灯盏花素能抑制豚鼠心室肌细胞的Ca2+内流,此作用具有电压依赖性、质量浓度依赖性、药物使用-刺激频率依赖性和可恢复性。

Objective To investigate the effects of breviscapine on slow inward calium current（ICa）in single ventricular cells of guinea pigs. Methods Whole-cell patch clamp technique was used. Results Breviscapine could obviously decrease lc. in a way of concentration and voltage-dependent mode, but had little effect on reversal potential. Breviscapine with the concentration of 5mg· L1, 10mg·L^-1, and 20 mg·L^-1 decreased Ic. by 5.4 %, 22.9 % and 45.0 %, respectively. When the stimulating frequency was changed, breviscapine facilitated the reduction of lc. through increasing clamp pulse frequency, and the inhibition of breviscapine was stronger at 0.5 s interval than that at 10 s. Conclusions Breviscapine decreases ICa in a voltage, concentration, use and frequency-dependence manner.