Experimental study on regeneration of ascending tract after spinal cord injury with predegenerated peripheral nerve graft and NGF infusion

Objective：To explore the effects of predegenerated peripheral nerve graft （PPNG） combined with nerve growth factor （NGF） infusion on ascending sensory tract regeneration after spinal cord injury. Methods： Fifty female SD rats were randomly divided into 5 groups. Group A was treated with PPNG and NGF infusion, group B with PPNG, group C with NGF infusion, group D and group E were blank and normal control, respectively. Horseradish peroxidase-labled （HRP） tracing method was employed to evaluate the regeneration of injured nerves after 8 weeks. The extent of regeneration in and beyond the nerve graft was determined by counting the number of HRP-labeled fibers intersecting imaginary lines perpendicular to the axis of the graft and cord. For the sake of convenience, according to the relation of the PNG and spinal cord, 6 model zones were divided, including caudal of spinal cord, caudal transition zone, caudal zone in graft, rostral zone in graft, rostral transition zone and rostral of spinal cord. Results： On the transverse section of caudal zone in graft, rostral zone in graft, rostral transition zone, the fibers in group A were significantly higher than that in group B and C （P〈0.05）. Conclusion： PPNG combined with NGF may significantly promote the regeneration of ascending long tract after spinal cord injury. The regenerative fibers can penetrate the 2 graft-host interface scars.

Experimental study on regeneration of ascending tract after spinal cord injury with predegenerated peripheral nerve graft and NGF infusion

Objective:To explore the effects of predegenerated peripheral nerve graft (PPNG) combined with nerve growth factor (NGF) infusion on ascending sensory tract regeneration after spinal cord injury. Methods: Fifty female SD rats were randomly divided into 5 groups. Group A was treated with PPNG and NGF infusion, group B with PPNG, group C with NGF infusion, group D and group E were blank and normal control, respectively. Horseradish peroxidase-labled (HRP) tracing method was employed to evaluate the regeneration of injured nerves after 8 weeks. The extent of regeneration in and beyond the nerve graft was determined by counting the number of HRP-labeled fibers intersecting imaginary lines perpendicular to the axis of the graft and cord. For the sake of convenience, according to the relation of the PNG and spinal cord, 6 model zones were divided, including caudal of spinal cord, caudal transition zone, caudal zone in graft, rostral zone in graft, rostral transition zone and rostral of spinal cord. Results: On the transverse section of caudal zone in graft, rostral zone in graft, rostral transition zone, the fibers in group A were significantly higher than that in group B and C (P<0. 05). Conclusion: PPNG combined with NGF may significantly promote the regeneration of ascending long tract after spinal cord injury. The regenerative fibers can penetrate the 2 graft-host interface scars.