氯胺酮对脊神经结扎大鼠脊髓背角星形胶质细胞的影响

EFFECT OF KETAMINE ON SPINAL ASTROCYTES IN RATS FOLLOWING SPINAL NERVE LIGATION

摘要:

目的：观察腹腔注射氯胺酮（KET）对脊神经结扎（SNL）大鼠脊髓背角星形胶质细胞的影响.方法：雄性SD大鼠42只随机分为五组：SHAM组;KET0组和NS0组结扎后分别腹腔注射KET 10mg/kg和生理盐水（NS）10 ml/kg;KET7组和NS7组,结扎7天后分别腹腔注射KET 10 mg/kg和NS.每组（除SHAM组）给药,每天两次,共7天.结扎后第4、7、14、21、28天行机械性痛敏实验,并用组化方法测定右侧脊髓背角胶质纤维酸性蛋白（GFAP）阳性细胞的变化.结果：与SHAM比较,KET0、NS0组机械痛敏试验的压力阈值（PWPT）下降,二者GFAP阳性细胞染色较SHAM深,GFAP免疫反应阳性产物表达相对面积分别增加45.0%（P＜0.01）和86.7%（P＜0.01）;与NS7比较,KET7组PWPT升高,KET7组GFAP阳性细胞染色较NS7组浅,相对面积（不同时段）分别下降40.3%（P＜0.01）和24.6%（P＜0.01）.结论：低剂量的KET能抑制星形胶质细胞的激活,从而起到治疗神经病理性疼痛的作用.

Abstract:

Objective:To investigate the effect of ketamine(KET) on spinal astrocytes in rat following spinal nerve ligation(SNL).Methods:Forty-two male SD rats weighing 180~220 g were randomly divided into 5 groups: SHAM group; KET0 group and NS0 group was respectively received intraperitoneal KET 10 mg/kg and NS 10 ml/kg immediately after spinal nerve ligation; KET7 group and NS7 group was respectively received intraperitoneal KET 10 mg/kg and NS 10 ml/kg 7 days after spinal nerve ligation.Pain threshold was estimated by measuring paw withdrawal response to Von Frey filament stimulation on the 4,7,14,21,28 day after SNL.The changes of spinal astrocytes were detected by immunohistochemistry ABC method.Results:In KET0 and NS0 groups PWPT was significantly decreased compared with SHAM group, the staining of GFAP immuno-reactive cells were heavier and the average areas were significantly larger than that in SAHM group (P<0.01). In KET7 group PWPT was significantly increased compared with group NS7. In KET7 group staining of GFAP immuno-reactive cells were lighter and the average areas were significantly smaller than that in group NS7(P<0.01). Conclusion: Low dose KET can attenuate the neuropathic pain by inhibiting the activation of astrocytes.