柴胡皂苷d对离体蟾蜍心脏功能的影响

Effect of Saikosaponin-d on the function of the heart isolated from toad

目的观察柴胡皂苷d对离体蛙心心率和心肌收缩力的影响。方法将60只健康蟾蜍分为空白对照组、不同浓度的柴胡皂苷d组(实验组)、维拉帕米组、维拉帕米+柴胡皂苷d组、艾司洛尔组、艾司洛尔+柴胡皂苷d组,每组10只,分别加入不同的药物;用BL-420生物机能实验系统测定每次给药后5 min内离体蛙心心肌收缩力及收缩频率的变化情况,记录蛙心心率和心力峰峰值,并采用变化率比较不同浓度柴胡皂苷d对正常离体蛙心心肌收缩力和心率的影响。结果不同终浓度的(0. 004 5、0. 009 0、0. 018 0 mmol/L)柴胡皂苷d对离体蛙心心率影响差异无统计学意义(P>0. 05),但可使离体蛙心的平均收缩力和心力峰峰值出现先逐渐上升、后逐渐下降;随着柴胡皂苷d浓度的增加,其对蛙心心力峰峰值的提高率逐渐升高,且有明显的药物浓度依赖性。柴胡皂苷d能够拮抗维拉帕米和艾司洛尔对离体蛙心心肌的抑制作用。结论柴胡皂苷d可使离体蛙心心肌收缩力先增强后减弱,其作用机制可能与激动心肌细胞上的β受体进而激活L型钙通道有关。

Objective investigate the effect of Saikosaponin-d on heart rate and myocardial contractility in the heart isolatedfrom a toad.Methods Sixty toads were divided into different groups including blank experimental,different concentrations of Saikosa-ponin-d,verapamil,verapamil+different concentrations of Saikosaponin-d,esmolol,esmolol + different concentrations of Saikosaponin-dgroups,each group consisting of 10 toads treated with different drugs. After treated for 5 minutes,heart rate and myocardial contractilitywere recorded with BL-420 biological function experimental system,then changes of heart rate and myocardial contractility were recor-ded to explore the mechanism.Results There was no significant difference on heart rate among different final concentration (0.004 5,0.009 0,0.018 0 mmol/L) Saikosaponin-d (P>0.05),but the mean contraction and peak cardiac force of the heart isolated from a toadboth ascended gradually and achieved a peak value in 35 s,afterwards descended gradually,Saikosaponin-d could antagonise verapam-il’s negative inotropic effect on myocardium. Conclusions Saikosaponin-d could make the change of its myocardial contractility fromstrengthening to attenuating,the mechanism of enhancement on myocardial contractility might be related to L-type calcium channel andβ-adrenoreceptor.