Abstract:

Objective To observe the effects of intrathecal injection of CXCR4 specific antagonist AMD3100 on rats of spared nerve injury (SNI) model. Methods A total of 60 male SD rats were randomly divided into 3 groups, i.e. sham group (n=10), control group (n=25), and AMD3100 group (n=25). SNI was adopted to establish the neuropathic pain model. Rats of AMD3100 group underwent continuous intrathecal injection of AMD3100 (1μg per mouse, once a day for two weeks), while rats of sham group and control group underwent intrathecal injection of the same volume of normal saline. The paw withdrawal threshold (PWT) under mechanical stimulus of affected extremities of rats was measured by Von-Frey filaments. The expression of glial fibrillary acidic protein (GFAP) in the hippocampus was detected by Western  blotting and immunofluorescence 14, 21, 28, and 35 d after first administration. Results Compared with sham group, PWT of control group significantly decreased after SNI operation and the expression of GFAP in the hippocampus increased. The continuous intrathecal injection of AMD3100 significantly increased the PWT of rats and down-regulated the expression of GFAP in the hippocampus. Conclusion The intrathecal injection of AMD3100 can down-regulate the expression of GFAP in the hippocampus of rats of SNI model and effectively alleviate symptoms of neuropathic pain of rats.

Key words: neuropathic pain, AMD3100, hippocampus, glial fibrillary acidic protein