P物质对培养脊髓星形胶质细胞谷氨酸代谢的影响

目的 观察P物质（SP）对脊髓星形胶质细胞兴奋性递质谷氨酸代谢的影响。方法 采用体外培养脊髓星形胶质细胞，施加SP刺激．分别采用^3H—Glutamate掺入和RT—PCR观察脊髓星形胶质细胞对谷氨酸摄取和转运体GLT-1表达的变化。结果 脊髓星形胶质细胞在SP的刺激下^,3H—Glu的摄取逐渐下降，10^-9mol／L与正常对照组差异有统计学意义（P〈0．05）．10^-8～10^-6mol／L组与正常对照组差异有统计学意义（P〈0．01）；脊髓星形胶质细胞GLT-1的表达在10^9-10^-8mol／L SP作用组和正常组差异无统计学意义（P〉0．05），10^-2～10^-6 mol／L SP刺激组GLT-1表达值低于正常对照（P〈0．05、P〈0．01）。结论 高浓度的SP作用下脊髓星形胶质细胞GLT-1表达和谷氨酸掺入下降，表明周围慢性疼痛可能通过致病递质SP使脊髓星形胶质细胞对谷氨酸的摄入减少，神经间隙谷氨酸堆积而导致脊髓中枢继发的神经损害。

Influence of SP on astrocyte of spinal cord on glutamate transport

Objective To explore the influence of SP on the astrocyte of spinal cord on glutamate transport.Methods The astrocyte of spinal cord was cultured in vitro and stimulated by SP,then ~3H-Glutamate incorporation and RT-PCR was made to investigate the glutamate intake and express of GLT-1 respectively.Results ~3H-Glutamate incorporation of the gruoups stimulated by SP decreased gradually at the concentration of SP 10~-9-10~-6 mol/L and had obvious difference with the control(P<0.05,P<0.01).No obvious difference of the express of GLT-1 was found between the groups stimulated by SP(10~-9-10~-8mol/L) and control(P>0.05) but the groups stimulated by SP(10~-7-10~-6mol/L) was lower than the control(P<0.05,P<0.01).Conclusion The ~3HGlu incorporation and express of GLT-1 of astrocyte of spinal cord stimulated by SP decreased obviously,which indicated the chronic surrounding pain might result in the secondary injury of nerve in spinal cord by the accumulation of glutamate because of the decrease of glutamate intake in astrocyte on the effect of SP.