The Influences Of FTY720Combined With Low-dose FK506on Functional Recovery After Acute Spinal Cord Injury In Rats

Objective: To observe the influences of FTY720combined with low-dose FK506on functional recovery after acute spinal cord injury (SCI) in rats.Methods: One hundred and fifty-two healthy adult female Sprague Dawley (SD)rats were randomly divided into five groups：A (Sham group),B (injury group),C(FK506-treated group),D (FTY720-treated group) and E (FTY720+FK506group). AT9T10laminectomy was then performed on each rat. The sham group,8rats,underwent laminectomy only, while animals in the other groups were subjected tospinal cord contusion using an Allen’s impactor.C group,36rats,fed withFK506(0.3ml/kg); D group,36rats, fed with FTY720(0.3ml/kg); E group,36rats,fedwith FTY720+FK506(0.3ml/kg); A and B group were fed with the same volumenormal saline. BBB scores were evaluated during7days after SCI. To evaluatepathological changes following injury, a1cm length of spinal cord were removed fromrats at6h、12h、24h、48h、72h and1w after injury.Using immunohistochemical methodto detective the glial fibrillary acidic protein (GFAP) and neurofilament protein(NF200)-positive cells. The image analysis software was used to calculate GFAP andgray value of NF200expression in each group. Data are expressed as the mean values±standard deviation. All data were analyzed using the Statistical Package for the SocialSciences version16.0. Differences between the five groups were analyzed using theone-way analysis of variance (ANOVA) followed by “Tukey test” for multiplepair-wise comparisons. A value of P <0.05was considered statistically significant.Results: Rats in C,D and E groups showed gradually recovey in motor function,and BBB scores were significantly higher than Group B.BBB scores in E group showed significantly higher than group C and D groups1w after injury(P<0.05).BBB scores ingroup E were reached to14.80±0.573w after injury.Rats in A group showed normalspinal cord morphology and function.Rats in group E showed the best changes in tersmof necrosis and function recovey, followed by D,C and B groups. GFAP andNF200-positive cells were statistically significant in C,D and E groups compared with Bgroup. There are differences between the C,D and E groups,The gray value of NF200expression in E group was the best,followed by Dand C groups(P<0.05).Conclusions: The motor functional recovery after acute spinal cord injury can beachieved with the treatment of FTY720combined with low-dose FK506. TheInfluences of FTY720combined with low-dose FK506is superior to FTY720or FK506respectively.The possible mechanisms for the motor functional recovery with thetreatment of FTY720combined with low-dose FK506were the reduction of GFAP andthe promotion of axonal growth.