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目的 探讨交感神经信号对大鼠正畸牙移动中牙根吸收的影响.方法 选取36只8周龄无特定病原体(SPF)级健康雄性SD大鼠建立正畸牙移动实验模型,随机分为普萘洛尔(PRO)组、异丙肾上腺素(ISO)组和对照组,每组12只.各组大鼠分别腹腔注射PRO[20 mg/(kg·d)]、ISO[5 mg/(kg·d)]和等体积的生理盐水.镍钛螺旋拉簧每周加力1次,3组动物于正畸加力14 d后处死.分离大鼠上颌骨及第一磨牙,采用苏木精-伊红(HE)染色光镜观察各组大鼠牙根吸收情况,并用MicroCT测量分析第一磨牙近中根的体积,比较各组之间的差异.应用SPSS 19.0对数据进行统计学分析.结果 HE染色显示PRO组的牙根表面吸收陷窝面积和深度与其他两组相比表现最轻,ISO组的牙根吸收程度较其他两组严重,可达牙本质.MicroCT结果显示PRO组的上颌第一磨牙近中根平均牙根体积明显大于对照组(P<0.01),ISO组的平均牙根体积小于对照组(P<0.05).结论 交感神经信号对正畸过程中根吸收有影响,神经激活会促进牙根吸收,神经抑制会减少牙根吸收.“,”Objective To explore the effects of sympathetic signals on root resorption in rats during orthodontic tooth movement. Methods Models of orthodontic tooth movement were established in 36 male 8-week old specific pathogen free (SPF) SD rats, which were randomly divided into 3 groups: propranolol (PRO) group, isoprenaline (ISO) group, and control group. The rats in the 3 groups were intraperitoneally injected with PRO[20 mg/(kg·d)], ISO [5 mg/(kg·d)] and isometric 0.9％ saline, respectively, and were executed with force once every 7 days. After 14 days, the rats were sacrificed. The maxillae and first molars were separated. The root resorption was observed with he-matoxylin-eosin( HE) staining. The volume of the mesial root of the first molars were measured with MicroCT. The differences among the 3 groups were compared using the SPSS 19. 0 software. Results The results of HE staining showed that root resorption pits appeared in all 3 groups. The depth and scope of root resorption pits were the most seri-ous in the ISO group, followed by the control and PRO groups. The results of MicroCT showed that the volume of me-sial root of the first molars in the PRO group was larger than that in the control group ( P<0.01) , while the volume in the ISO group was obviously smaller than that in the control group ( P<0.05) . Conclusion Sympathetic signals can in-fluence the root resorption during orthodontic tooth movement. The activation of signals promotes root resorption while the suppression of signals inhibits resorption.