目的 评价鞘内注射雷帕霉素对CCI神经病理性痛大鼠的痛阈及脊髓背角胶质细胞表达的影响。方法 健康雄性SD大鼠30只随机分为6组:①CCI组:CCI术后14天处死;②正常对照组:不做任何处理; ③前对照剂组:鞘内置管3天后行CCI术,术后4小时后鞘内给同体积生理盐水,连给3天; ④前给药组:鞘内置管3天后行CCI术,术后4小时鞘内给雷帕霉素溶液,连给3天; ⑤后对照剂组:鞘内置管3天后行CCI术,术后7天鞘内给同体积生理盐水,连给3天;⑥后给药组:鞘内置管3天后行CCI术,术后7天鞘内给雷帕霉素溶液,连给3天。各组于CCI术前1天和术后第2、4、6、8、10、12、14天测机械痛阈和热痛阈。术后14天测痛后用多聚甲醛灌注大鼠,取L4~5脊髓,免疫组化染色,星形胶质细胞标记蛋白(GFAP)检测星形胶质细胞表达变化,并定量分析。结果 与对照组相比,CCI手术组热痛阈和机械痛阈从CCI手术后第4天开始下降(P<0.05);前后给药对照剂组与CCI组相比,差别无统计学意义(P>0.05)。前给药组痛阈从CCI手术后第4天开始上升并持续至手术后第14天,与CCI组相比,差别有统计学意义 (P<0.05)。与CCI组相比,后给药组痛阈从CCI第8天开始上升并持续至手术后第14天,差别有统计学意义(P<0.05)。 与正常对照组比较,CCI组、前、后对照剂组手术侧脊髓背角GFAP染色阳性区平均光密度与阳性面积均有增加,差别有统计学意义(P<0.05)。前、后给药组手术侧GFAP染色阳性区平均光密度与阳性面积与CCI组比较,均有明显降低,差别有统计学意义(P<0.05)。结论 鞘内注射雷帕霉素可缓解大鼠神经病理性痛,并抑制脊髓背角胶质细胞的激活。

Objective To evaluate the effects of intrathecal injection of rapamycin on pain threshold and spinal cord gliacyte activation in rats of neuropathic pain. Methods Healthy 30 male SD rats were randomly divided into 6 groups(n=5 in each group): ① control group without operation or intrathecal injection. ②CCI group without intrathecal injection. ③ intrathecal injection of rapamycin 10 μg(10 μL) 4 hours after CCI operation and the next 2 days once a day. ④ intrathecal injection of NS10 μL 4 hours after CCI operation and the next 2 days once a day. ⑤ intrathecal injection of rapamycin 10 μg(10 μL) 7 days after CCI operation and the next 2 days once a day.⑥ intrathecal injection of NS10 μL 7 days after CCI operation and the next 2 days once a day. Mechanical and thermal threshold were tested 1 day before the CCI operation and 2^th、4^th、6^th、8^th、10^th、12^th、14^th days after the CCI operation for all the rats. Lumbar segment of spinal cords was removed for determination of glial fibrillary acidic protein(GEAP) in spinal cord by immuohistochemistry dyeing and assay in the 14th day after CCI operation for all the rats. Results Mechanical and thermal hyperalgesia emerged on 4th day and maintained till 14th day after CCI operation(P<0.05). After intrathecal injection of rapamycin 4 hours or 7days after CCI, mechanical and thermal threshold significantly increased compared to intrathecal injection of NS(P<0.05). And the sum area of GFAP positive and the mean density of GFAP positive area in the dorsal horn of operation side greatly increased in rapamycin treated groups compared NS treated groups(P<0.05). Conclusion Intrathecal injection of rapamycin may attenuate CCI induced hyperalgesia and inhibit the activation of astrocyte.