大鼠腰椎腹侧神经根牵拉模型的建立

Establishment of a rat model of lumbar spinal root avulsion

目的为了研究肌萎缩侧索硬化症致病机理和药物研发,建立第4腰椎腹侧神经根牵拉大鼠模型,并用脑源性神经营养因子作为阳性药物进行模型的有效性验证。方法首先对5只SD雄性大鼠进行手术,一周后用抗胆碱乙酰转移酶抗体进行免疫组织化学染色观察脊髓前角运动神经元数量的变化;预实验证明手术模型成功后,将40只7周龄SD雄性大鼠随机分为四组,两组模型对照组及两个脑源性神经营养因子治疗组(手术后立刻预防性给药组和手术后一周治疗性给药组)。使用抗胆碱乙酰转移酶免疫组织化学染色观察运动神经元数量的变化。结果大鼠手术后恢复良好,临床观察无异常。染色结果证明手术牵拉后,造成明显的脊髓前角运动神经元变性死亡。与对照组相比,用脑源性神经营养因子治疗的神经根牵拉动物,不管是预防性给药还是手术1周后再进行治疗性给药都达到了良好的治疗效果,胆碱乙酰转移酶染色阳性神经元细胞数量显著增加(P<0.0001),结果分别为17.85%比93.06%;26.6%比87.27%。结论成功的建立大鼠第4腰椎腹侧神经根牵拉模型,为肌萎缩侧索硬化症的研究提供了一种有价值的动物模型。

Objective To establish a rat model of spinal root avulsion and to validate the model by brain-derived neurotrophic factor（ BDNF） treatment. Methods To evaluate the motor neuron loss,5 male SD rats were used to undergo spinal root avulsion surgery. One week later,the number of motor neurons in the ventral horn of the spinal cord was assessed by histopathology using immunohistochemical staining with a choline acetyl transferase（ Ch AT） antibody. After this pilot study,40 male SD rats at 7 weeks of age were randomly divided into 4 groups： two control groups,BDNF preventive and treatment groups. Results All rats recovered well post-surgery and no obvious abnormality was observed. Compared with the contralateral side,the number of motor neurons in the ipsilateral avulsed side was significantly decreased at one week after surgery（ 20. 06%,P〈0. 05）. Compared with the control group,there was a significant increase in Ch AT positive neurons in the BDNF preventive group（ 17. 85% vs. 93. 06%,P〈0. 0001） or BDNF treatment group（ 1 week after surgery）（ 26. 94% vs. 86. 87%,P〈0. 0001）,indicating that the motor neurons were effectively protected by BDNF.Conclusions A rat model of spinal root avulsion is successfully established,which can be valuable for studies of amyotrophic lateral sclerosis and drug discovery efforts.