Objective: To study the change in expressions of nerve growth related protein (GAP-43) and neurofilament (NF) after experimental injury of spinal cord, and the regulatory effect of Chinese medicine Suifukang (SFK) on them.
Methods: Forty-eight from the 54 selected adult SD rats were established into spinal cord injury model by making hemitransection at the T12 level, and randomly divided into two groups, the SFK group feed with SKF contained liquor and the model group feeding with equal volume of saline. The another 6 rats were untreated and taken as the normal group. All rats were sacrificed in batches at different time points of day 3, 7, 15 and 30 after modeling. The spinal cord was obtained for determining the optic density (OD) of positive expression of GAP-43 and NF with immunohistochemical stain by microscopic and semi-quantitative image analysis.
Results: (1) OD of NF in the model group was obviously decreased on day 7, showing significant difference to that in the normal group and that in the SFK group (P < 0.05), and it maintained at low level after then, while the OD of NF in the SFK group was obviously higher than that in the model group (P < 0.05), it arrived the peak on day 15 and then dropped near the level in the normal group on day 30; (2) OD and of GAP-43 in the model group obviously decreased on day 3 (P < 0.05), showing significant difference to that in the normal group (P < 0.05), then it returned to approach to the level in the normal group on day 7. It was higher in the SFK group than in the model group on day 3, and maintained the high level to day 7, at that time, it was still higher than that in the model group and also higher than that in the normal group (P < 0.05).
Conclusion: SFK can promote the repair and regeneration of injured nerve fibers in spinal cord by up-regulating the expression of GAP-43 and NF.