骨癌痛大鼠脊髓背角Nogo-A及其受体NgR1表达的变化

Changes in expression of Nogo-A and its receptor NgR1 in the spinal dorsal horn in a rat model oftibial bone cancer pain

目的 观察骨癌痛大鼠脊髓背角Nogo-A 及其受体NgR1 表达的变化。方法 雌性未交配SD 大鼠60 只，体重160～200 g，采用随机数字表法将其分为两组（n=30）：假手术组（S 组）和骨癌痛组（BCP组）。BCP组于左侧胫骨骨髓腔内注射5 μl Walker256 乳腺癌细胞制备骨癌痛模型，S 组左侧胫骨骨髓腔内注射生理盐水5 μl。选用von Frey 纤维丝检测各组大鼠造模前1 d 及造模后3、7、14、21 d 机械缩足阈值（MWT），评价疼痛行为学变化。于造模后7、14、21 d痛阈测定后取大鼠L 4～5脊髓背角，采用Western Blot法测定 Nogo-A及其受体NgR1的表达。结果 与S组比较，BCP组肿瘤细胞接种后第7 天 MWT［（3.63±1.61）g］、第14天MWT［ （2.53±1.39）g］、第21天MWT［（2.40±1.16）g］降低（P＜0.05）；与 S 组比较，BCP 组大鼠术后7、14、21 d 脊髓背角Nogo-A 及其受体NgR1 表达上调（P＜ 0.05）。结论 脊髓背角Nogo-A 及其受体NgR1 可能参与了骨癌痛机械痛敏的形成。

Objective To investigate the expression of Nogo-A and its receptor NgR1 in the spinal dorsal horn in a rat model of tibial bone cancer pain. Methods A total of 60 female non-copulatory Sprague- Dawley（ SD） rats weighting 160-200 g were randomly divided into two groups（ n=30）：sham operation group（ Group S） and bone cancer pain group（ Group BCP）. Group BCP received injection of 5 μl Walker-256 breast cancer cells in pulp cavity of left side of tibia, and Group S received injection of 5 μl normal saline. The Mechanical Withdrawal Threshold（ MWT） of rats in each group were measured using von Frey filaments to assess pain behavioral changes on 1d before operation and 3, 7, 14 and 21 d after operation. The rats were then sacrificed and L 4～5 segments of the spinal cord were removed for determination for Nogo-A and its receptor NgR1 expression in spinal dorsal horn by Western Blot after pain threshold measurement on 7, 14 and 21 d after operation. Results Compared with Group S, the MWT was significantly decreased at 7 d MWT[ （3.63±1.61）g], 14 d MWT [（2.53±1.39）g] and 21 d MWT[ （2.40±1.16）g] in Group BCP（ P 〈 0.05）. Compared with Group S, the expression of Nogo-A and its receptor NgR1 was significantly increased at 7, 14 and 21 d in Group BCP（ P〈0.05）. Conclusions Nogo-A and its receptor NgR1 in the spinal dorsal horn may involve in the development of tibial bone cancer pain.