The effect of b FGF on the expression of NMDA receptor in spinal cord of rat with neuropathic pain

Objective To investigate the role of basic fibroblast growth factor( b FGF) and its effect on the expression of N-methyl-D- aspartate receptor in rat spinal cord with neuropathic pain. Methods Forty-eight male SD rats were randomly divided into four groups( n = 12) : sham group( group A),sham + b FGF antibody group( group B),neuropathic pain group( group C),neuropathic pain + b FGF antibody group( group D). Neuropathic pain model was produced by spared nerve injury( SNI). b FGF antibody 18 μg( 40 μL) was injected intrathecally on 1,6,9,13,16 and 20 days after operation in group B and D. The equal volume of phosphate buffered saline was injected intrathecally in group A and C at the same time. The paw withdrawal mechanical threshold( PWMT) was measured on 1,4,7,14 and 21 days after operation and 1 day before operation. Rats in each group were sacrificed on 21 d after operation and the lumbar segments of the spinal cord( L4-6) were collected. The expressionlevel of glial fibrillary acidic protein( GFAP) was detected by immunohistochemical analysis; The expression of Nmethyl-D-aspartate receptor 1 subunit( NR1),N-methyl-D-aspartate receptor 2 subunit( NR2 A or NR2B) were detected by RT-PCR and Western blot. Results Compared with group A and B,the level of PWMT was decreased and the expression of NR1 and NR2 B in spinal cord was increased in group C and D( P 0. 05). Compared with group C,the level of PWMT was increased and the expression of NR1 and NR2 B in spinal cord was decreased in group D( P 0. 05). Conclusions b FGF can reduce degree of neuropathic pain in rat with neuropathic pain induced by SNI,and the effect of b FGF on expression of NMDA receptor may associate with this phenomenon.