米诺环素对神经病理性疼痛大鼠脊髓星形胶质细胞激活的影响

目的观察米诺环素对CCI大鼠脊髓水平GFAP表达,探讨脊髓星形胶质细胞在神经病理性疼痛中的不同时程作用。方法将110只SD大鼠随机分成5组:A组:对照组(n=15)、B组:假手术组(n=25)、C组:CCI对照组(n=25)、D组:CCI预给药组(n=25)、E组:CCI治疗组(n=25)。分别测定各组在手术前(以第0天表示)以及手术后第1、4、7、11、14天损伤侧后肢50%机械刺激缩足阈值,然后相应分别取每组大鼠L4-6段脊髓,采用免疫组化染色方法测定脊髓背角星形胶质细胞GFAP表达变化情况。结果①坐骨神经结扎后大鼠出现痛觉过敏且持续增强存在。②B组和D组亦可见星形胶质细胞有轻微的激活,C组脊髓背角星形胶质细胞在术后7d发生明显激活,至术后14d星形胶质细胞被强烈的激活;E组星形胶质细胞术后有较明显的激活但无高峰期。结论脊髓水平星形胶质细胞的激活可能对神经病理性疼痛的产生维持发挥重要作用;米诺环素术前给药抑制星形胶质细胞的激活,减轻神经病理性疼痛。

Effect of minocycline on the the activation of the spinal astrocyte in the neuropathic pain rat

Objective To observe the effect of minocycline on spinal astrocytic GFAP in CCI rats in order to investigate the role of astrocytic and provide a new treatment in neuropathic pain.Methods 110 SD rats were randomly divided into 5 groups.Group A,control without intervention group(n=25).Group B,sham group(n=25).Group C,normal saline administered group(n=25).Group D(n=25),preemptively treated group;Group E(n=25),post operation treatment group.Animal mechanical allodynia was represented by 50% paw drawal threshold filaments.In group C,group D and group E,the same dose of minocycline or saline was administered after operation.And five rats were randomly chosen at timepoint of day 1,day 4,day7,day 11,day 14 after surgery to evaluate the activation of astrocyte,by examining spinal GFAP with immunohisto chemical technique.Results ① The mechanical allodynia appeared after surgery,maintaining and strenting throughout the whole experiment.②GFAP immunoreactivity in group C was observed at day 7 and reached peak at day 14.Significant astrocyte activation in group E.Mild astrocyte activation in group B and group D were observed.Conclusion Astrocyte activation in spinal cord might paly an important role in neuropathic pain,and preemptively treatment of minocycline could alleviated neuropathic pain.