Cdk5抑制剂Roscovitine对神经病理性疼痛大鼠痛行为学的影响及机制

摘要

Objective To evaluate the effect and mechanism of Cdk5 inhibitor Roscovitine on pain behavior of rats with neuropathic pain.Methods Sixty-four SPF Sprague-Dawley male rats were randomly divided into 5 groups:the normal control group (group N, n=8), sham operation group (group S, n=8), chronic constriction injury of sciatic nerve (CCI) group (group I, n=8), CCI+solvent (group D, n=8), and CCI+Roscovitine (group R, n=32).Neuropathic pain was produced by CCI in rats at 7 days after catheterization of the spinal subarachnoid space.Rats in the group N did not receive any treatment, the sciatic nerve of rats in the group S was exposed but was not ligated.5％DMSO (20μL) was injected intrathecally into the rats of the group D, and 100 ug Roscovitine (in 20μL 5％DMSO) was injected intrathecally into the rats of group R at 7 days after CCI.At 1 d (T0) before CCI, 3 d (T1), 5 d (T2) and 7 d (T3) after CCI, and 0.5 h (T4), 2 h (T5), 6 h (T6) and 12 h (T7) after administration, the paw withdrawal mechanical threshold (PWMT) and paw withdrawal thermal latency (PWTL) were all measured.Rats in the groups N, S, and I were sacrificed on day 7 after CCI without intrathecal injection.Rats in the group R were sacrificed at 0.5, 2, 6 and 12 h after intrathecal injection on day 7 after CCI.Rats in the group D were sacrificed after intrathecal injection of 5％DMSO (20μL) on day 7after CCI.The expression of GFAP in the spinal cord astrocytes was determined by Western blotting.Results Compared with the group S, PWMT and PWTL in the group I, group D, and group R decreased at different time points after operation (all P＜0.05).Compared with the group D, PWMT increased and PWTL increased during T5 to T7 in the group R (P＜0.05).Compared with the group S, GFAP protein expression in the dorsal horn of spinal cord in the groups I, D, and R at T4, T5, T6, and T7was significantly up-regulated (all P＜0.05).Compare with the group D, GFAP expression in dorsal horn astrocytes of spinal cord at T5, T6and T7after intrathecal injection in the group R was significantly down-regulated (P＜0.05).Conclusion Cdk5 inhibitor Roscovitine can alleviate neuropathic pain in rats caused by sciatic nerve ligation, and its mechanism may be related to inhibition of GFAP protein expression.%目的 观察Cdk5抑制剂Roscovitine对神经病理性疼痛大鼠痛行为学的影响,并探讨其机制.方法 选择SD大鼠64只,随机分为正常对照组(N组)8只、假手术组(S组)8只、坐骨神经结扎(CCI)组(I组)8只、CCI+溶剂组(D组)8只,剩余32只作为CCI+给药组(R组).I组、D组和R组行鞘内置管7天后,采用CCI法建立神经病理性疼痛模型,N组不做任何处理,S组暴露坐骨神经但不予结扎.术后第7天,D组鞘内注射5％二甲基亚砜20μL,R组鞘内注射Cdk5抑制剂Roscovitine 100μg,N组、S组和I组不注射药物.分别于术前(T0)、术后3天(T1)、术后5天(T2)、术后7天(T3)以及给药后0.5(T4)、2(T5)、6(T6)、12 h(T7),检测各组机械性缩足阈值(PWMT)、热缩足潜伏期(PWTL).腹腔注射麻醉后,取各组脊髓腰膨大处(L4～L6)组织,采用Western blotting法检测脊髓星形胶质细胞胶质纤维酸性蛋白(GFAP)表达.结果 与N组、S组比较,I组、D组和R组术后各时间点PWMT、PWTL均明显降低(P均＜0.05);与I组相比,R组给药后T5～T7时PWMT、PWTL均明显升高(P均＜0.05).与S组比较,I组、D组和R组T4～T7时脊髓星形胶质细胞GFAP表达均明显上调(P均＜0.05);与D组比较,R组给药后T5～T7时脊髓星形胶质细胞GFAP表达均明显下调(P均＜0.05).结论 Cdk5抑制剂Roscovitine可减轻大鼠神经病理性疼痛,其机制可能与抑制脊髓星形胶质细胞GFAP表达有关.