The animals were killed at 7 d after operation and the L4-5 segment of the spinal cord was removed for determination of expression of IL-6 mRNA ( by RT-PCR) and IL-6 protein (by immuno-histochemistry) .

• 术后7 d测定热痛阈后立即处死大鼠；取L4.；5脊髓组织；其中4只用于免疫组化实验(测定IL-6表达)；另外4只用于RT-PCR实验(测定IL-6 mRNA表达)。