目的 观察桂枝对麻黄Ephedrae Herba中麻黄碱（E）、伪麻黄碱（PE）小鼠脑组织内分布动力学的影响。方法 分别ig给予小鼠麻黄、麻黄桂枝药对水煎液，于不同时间点采集脑组织样本，采用气相色谱-质谱联用（GC-MS）测定脑组织中E、PE的经时变化，以Kinetica 5.0.11软件，对脑组织中E、PE进行非房室动力学拟合，计算E、PE的组织动力学参数，从而评价桂枝对麻黄中E、PE在脑组织内分布动力学的影响。结果 麻黄桂枝配伍组中E、PE脑内t_max较麻黄组延迟，AUC_0-∞降低，E的MRT_0-∞缩短。结论 桂枝配伍麻黄能通过延缓麻黄中E、PE在小鼠脑组织中的分布过程，降低脑内累积分布量，同时加快E、PE在脑内的消除，从而发挥减毒作用，证实桂枝与麻黄间存在相畏、相杀的配伍作用。

Objective To observe the effect of Cinnamomi Ramulus on the distribution kinetics of ephedrine (E) and pseudoephedrine (PE) from Ephedrae Herba in brain tissues of mice. Methods Mice were ig adminstered by Cinnamomi Ramulus and codecoction of Cinnamomi Ramulus combined with Ephedrae Herba. Brain tissues of mice were collected at different time after drug administration. The variation of E and PE with time was determined by GC-MS method. The non compartmental kinetic was fitted and the parameters were calculated by Kinetica 5.0.11 software, so as to evaluate the effect of Cinnamomi Ramulus on the distribution kinetics of E and PE from Ephedrae Herba in brain tissues of mice. Results Compared with the Ephedrae Herba group, in the group with the codecoction of Cinnamomi Ramulus combined with Ephedrae Herba, the t_max of E and PE distributed in the brain tissues of mice was delayed, the AUC_0-∞ of E and PE in the brain tissues of mice under the drug concentration curve was smaller and the MRT_0-∞ of E was reduced. Conclusion Cinnamomi Ramulus combined with Ephedrae Herba has the propertis of delaying the distribution process of E and PE, reducing the cumulative distribution volume, and accelerating the elimination of E and PE in the brain tissues of mice. Above all, Cinnamomi Ramulus can relieve the neurotoxicity of Ephedrae Herba, and there is the combination function of mutual restraint and mutual supression between the two drugs.

国家自然科学基金资助项目（81001496）；成都中医药大学科技发展基金（ZRMS201239）