【摘要】 目的 选择马钱子散的药效学观测指标;探讨以药效为指标的中药动力学研究方法;为马钱子散的合理用药提供实验依据。方法 健康清醒家兔，灌胃给药，以单个脉冲刺激坐骨神经根部，观测其远端肌肉诱发电位的潜伏期，比较用药前后潜伏期的变化。以动物各自药前的潜伏期为标准，将药后潜伏期转化为药前的百分率(E%)及百分变化率(△E%)，再进行统计分析及药物量效关系和时效关系的研究。用效量逐点转换法和房室模型拟合法进行效量动力学参数估算。结果 在一定剂量范围内，马钱子散用药后其潜伏期明显缩短(P<0.01),其药效强度与给药剂量正相关(r=0.9544，P<0.05)，其量效关系可用直线回归方程Δ=4.5683×LnD-10.59来表达，式中LnD为对数剂量，Δ%为相应剂量下药效强度的估算值。其40mg/kg的时效关系可用多项式Δ%=1.654919-0.240459t+0.021403t2-0.00464t3+4.248E-06t4-1.788E-08t5+2.855E-11t6来表达，式中t为给药后的间隔时间。其效量动力学过程基本符合血管外给药的二室开放模型。其主要动力学参数ka=0.0661min-1; t1/2a=10.5min;α=0.0506min-1;t1/2α=13.7min;β=0.0059min-1;t1/2β=118.1min。 结论 诱发电位的潜伏期，可作为马钱子散进行药效学和效量动力学研究的观测指标,其效量动力学的主要参数值与其主要有效成分士的宁的药代动力学参数相近，可为临床合理用药作参考。

    【关键词】 马钱子; 药效; 药物动力学; 肌电图; 潜伏期

    Effect and pharmacodynamics on the latent period of the electromyogram of MQZ pulvis in rabbit

    Li Zhao-hui, LI Cheng-shao, WANG Zhu-mei,et al. Zhongshan Hospital of Xiamen University, Xiamen 361004，China

    【Abstract】 Objective To select effective guideline and discuss the method on pharmacodynamics of Chinese medicine, and provide parameters on pharmacodynamics of MQZ pulvis. Methods The rabbits which were health and clear-headed were given MQZ pulvis with gastric injection. Stimulating the root of sciatic nerves with single impulse, observing the latent period of the electrical activity of the muscles of far off end, comparing the changes, that between before and after administration. The latent period after administration was changed to percent ratio by using that of the same rabbit before administration as a standard. Studying the relations of the dose-effect and time-effect, and estimating the parameter of pharmacodynamics by using compartment model method. Results The latent period after administration has reduced obviously (P<0.01). The dose-effect is positive correlation, and that could be described by : Δ=4.568.3×LnD-10.59.In this the LnD is a logarithm dose. The Δ% is a estimate value of drug effect with a certain dose. The curve of time-effective dose after MQZ pulvis 40mg/kg i.g. was found to fit a two- compartment open model with the first order elimination. The apparent parameters of the pharmacodynamics were: ka=0.0661min-1; t1/2a=10.5min; α=0.0506min-1; t1/2α=13.7min; β=0.0059min-1; t1/2β=118.1min. Conclusion The latent period of electrical activity of the muscles could be as a guideline, which could be used to research the dose-effect and pharmacodynamics of MQZ pulvis. The parameter of pharmacodynamics of MQZ pulvis is close to that of the efficient in gredient of it strychnine and it could be the reference of clinical use. ......