Abstract: Objective To observe the effect of bone marrow mesenchymal stem cells (BMSCs) transplantation on the expression of growth associated protein-43 (GAP-43) in rats after spinal cord injury (SCI). Methods The SCI models were made by impacting at the level of T11 segment. After modeling, the rats were randomly and equally divided into control group (n=18) and observation group (n=18). 1 week after injury, DMEM/F12 medium 0.1 ml was injected into tail vein of rats in the control group, and an equal volume of BMSCs suspension was injected in the observation group. 1, 2, 4, 8 weeks after SCI, the hindlimb function was evaluated by the Basso-Beattie-Bresnahan (BBB) score. 2, 4, 8 weeks after SCI, the expression of GAP-43 mRNA was detected by RT-PCR, and the expression of GAP-43 was detected by the immunohistochemistry. Results 2, 4, 8 weeks after SCI, compared with the control group, The BBB score increased, the expression of GAP-43 mRNA and GAP-43 increased in the observation group (P<0.05). Conclusion BMSCs transplantation can improve the expression of GAP-43 in gene and protein level, and then promote the repair of SCI.

Key words: spinal cord injury, bone marrow mesenchymal stem cells, transplantation, growth associated protein-43, rats