神经病理性疼痛致抑郁大鼠海马促炎细胞因子含量的变化

摘要

目的 观察神经病理性疼痛致抑郁大鼠海马促炎细胞因子含量的变化,并探讨其与抑郁严重程度的关系.方法 成年雄性SD大鼠28只,随机分为两组:假手术组(Sham组)和保留性坐骨神经损伤组(SNI组),每组14只.于术前1 d及术后7、14、21 d测试机械痛阈值(MWT);于术前1~3 d测试糖水偏好、强迫游泳实验基础值;术后21~23 d进行糖水偏好实验、强迫游泳实验;行为学测试结束后取海马组织,采用ELISA法检测海马中IL-1β、IL-6、TNF-α的含量,并对其与糖水偏好的相关性进行分析.结果 与Sham组比较,SNI组大鼠在术后7、14、21 d MWT明显降低(P<0.001),术后21 d糖水偏好明显降低(P<0.01),术后23 d强迫游泳不动时间明显延长(P<0.05);术后21 d海马组织IL-6、TNF-α含量明显升高(P<0.05或P<0.01),而IL-1β含量差异无统计学意义;SNI组海马组织IL-1β(r2=0.60,P<0.01)、IL-6(r2=0.55,P<0.01)、TNF-α(r2=0.60,P<0.01)含量与糖水偏好呈明显负相关.结论 神经病理性疼痛致抑郁大鼠海马促炎细胞因子IL-6、TNF-α含量升高,且与抑郁严重程度呈负相关.%Objective To observe changes of hippocampal levels of pro-inflammatory cytokines in rats with neuropathic pain-induced depression, and to explore the relationship between hippocampal levels of pro-inflammatory cytokines and severity of depression.Methods Twenty-eight adult male rats were randomly divided into two groups: group sham (n=14) and spared nerve injury (group SNI) (n=14).Mechanical withdrawal thresholds (MWT) were measured 1 day before and 7, 14 and 21 days after operation.Sucrose preference test and forced swim test were tested 1-3 days before and 21-23 days after operation.After test, hippocampus was collected.The hippocampal levels of interleukin (IL)-1β, IL-6 and tumor necrosis factor-α (TNF-α) were measured by ELISA.Correlational relationships between hippocampal levels of pro-inflammatory cytokines and sucrose preference were evaluated.Results Compared with group sham, MWT was decreased 7, 14, 21 days after operation (P<0.001).Group SNI displayed decreased sucrose preference 21 days after operation (P<0.01) and increased immobility time in FST 23 days after operation (P<0.05).The levels of IL-6 and TNF-α were increased in hippocampus (P<0.05 or P<0.01).No significant difference was observed in IL-1β.The hippocampal levels of IL-1β (r2=0.60,P<0.01), IL-6 (r2=0.55,P<0.01) and TNF-α(r2=0.60,P<0.01) were negatively correlated with sucrose preference.Conclusion The hippocampal levels of pro-inflammatory cytokines IL-6 and TNF-α are increased in rats with depression induced by neuropathic pain, and the levels of hippocampal pro-inflammatory cytokines are negatively correlated with the severity of depression.