福尔马林诱导单核细胞趋化因子在脊髓星形胶质细胞中的表达

目的:研究小鼠足底注射福尔马林诱导的急性炎症性疼痛和单核细胞趋化因子(MCP-1)在脊髓中的表达。方法:将5%的福尔马林注射到小鼠左侧足底,观察注射后1 h内动物的自发性疼痛。采用ELISA方法检测不同时间点MCP-1在脊髓中的表达。运用免疫荧光双标观察MCP-1在脊髓中表达的细胞类型。结果:福尔马林外周注射引起了典型的双时相自发性疼痛。在注射后10 min,MCP-1在脊髓中的表达显著升高(P<0.05),1 h和3 h与正常组相比差异无统计学意义(P>0.05)。免疫荧光双标结果显示,MCP-1与星形胶质细胞的标记物GFAP共存,与神经元的标记物NeuN不共存。结论:外周注射福尔马林引起MCP-1在脊髓星形胶质细胞中快速而短暂的表达升高。MCP-1可能参与福尔马林引起的第二时相的疼痛。

The expression of monocyte chemoattratant protein-1 in spinal cord astrocytes induced by formalin

Objective: To investigate the pain behavior and the expression of monocyte chemoattractant protein-1(MCP-1) in the spinal cord after peripheral injection of formalin.Methods: 5% formalin was injected into the unilateral hindpaw of mice.Spontaneous pain behavior was observed for 1 hour after injection.ELISA was used to detect the expression of MCP-1 in spinal cord at different time points after formalin injection.Immunofluorescence staining was used to check the cellular localization of MCP-1 in the spinal cord.Results: Peripheral injection of formalin induced typical two-phase spontaneous pain.MCP-1 was significantly increased in the spinal cord at 10 min(P<0.05),but not at 1 h or 3 h(P>0.05).Immunofluorescence staining showed that MCP-1 was colocalized with astrocytic marker,GFAP,but not with neuronal marker,NeuN.Conclusion: Peripheral injection formalin induced rapid and transient MCP-1 upregulation in the spinal cord astrocytes.The increased MCP-1 may be involved in the development and maintenance of second phase of the formalin-induced pain.