目的：探讨甘草酸协同麻黄碱的平喘作用机制。方法：利用基于CHO细胞的β₂肾上腺素受体（β₂-AR）激动药活性评价体系，豚鼠离体气管收缩和组胺引喘的活体动物模型观察甘草酸和麻黄碱联用的协同平喘效果。结果：甘草酸自身不能引起离体气管平滑肌舒张，平喘效果也不显著，但与麻黄碱联用可以通过提高β₂-AR的激动效果，明显增强平喘效果。结论：甘草酸通过调节β₂-AR信号通路增强麻黄碱的作用效果，两者联用有良好的协同作用。

Objective: To investigate the anti-asthmatic mechanism of combination of glycyrrhizic acid and ephedrine. Methods: With cell evaluating systems of β₂ adrenergic receptor (β₂-AR) agonists established by our laboratory, model of spasmolytic activities in vitro and antitussive activities in vivo, the effect of combination use of glycyrrhizic acid and ephedrine was observed. Results: In our study, glycyrrhizic acid alone showed little anti-asthmatic effect and could not relax the airway smooth muscles. However, it could enhance the anti-asthmatic activity of ephedrine when these two compounds were used together. Conclusion: Glycyrrhizic acid could increase bronchodilation activity of ephedrine through β₂-AR signal pathway and has synergistic effect on anti-asthmatic treatment.