The Effect Of FK1706 On GAP-43 Expression And Histological And Ethological Studies In Rats After Acute Spinal Cord Injury

ObjectiveTo study the effect of FK1706 on GAP-43 expression and histology and ethology in rats after acute spinal cord injury, to investigate the efficacy after acute spinal cord injury.Methods150 male SD rats were randomly divided into 3 groups: group A( sham group),group B(group after ASCI), group C(FK1706 group after ASCI). The clip compressive T10 spinal cord injury model in rats was established primarily. Group A underwent laminectomy without spinal cord injuries. Group B underwent the clip compressive operation of spinal cord. Group C underwent group B’s operation, and then Fk1706(1.0mg/kg) was transferred into the rats via the tail vein injection once daily for four weeks. Meanwhile, group A and B received the same dosage of 0.9%sodium chloride solution at the same time. At day 1st, 3rd, 7th, 14 th,,28 th post-operation, the rats’ functional recovery was evaluated by BBB score(Basso,Beattie and Bresnaha). The histology of the spinal cord tissue at the damage area was observed under the optical microscope with HE dyeing at the same interval post-operation. The expression of GAP-43 m RNA was detected by real-time PCR and presented by agar gel electrophoresis.SPSS19.0 was used for statistical analysis of data with a one-way analysis of variance, according to homogeneity of the variance,test(LSD-t)and Tarnhane’s T2 test were adopted and statistical significance was set for P<0.05.Results1. RT-PCR:The positive expression of GAP-43 mRNA were detected in all groups at all time points after ASCI. Group A maintained the low expression, there was not obvious fluctuation during the experimental observation. The expression of GAP-43 in all groups was not statistically significant at day 1st(P>0.05). At day 3rd after injury, the expression of GAP-43 in group B and C increased and reached their own zenith at day 7th and then decreased, the expression was higher than that in group A(P<0.05). All groups were low expression at the base line level.2. HE dyeing: Organization and cell inflammatory edema were the most significant feature in group B and C at the early phase after ASCI in HE staining, and cavities were observed under the light microscope gradually. A large number of condensed glial scars were observed in group B. the density of glial cells decreased more dramatically in the FK1706 group than that in group B.3. BBB score: The BBB score of group A is higher than that of group Band C at all times(P<0.05). At the 7th 、14th and 28 th day after SCI group C showed significantly increase in average BBB scores than group B(P<0.05).ConclusionsFK1706 can strengthen the production of GAP-43 and reduce the formation of neural glial scars so that it could promote the regeneration of axons after ASCI.