Effects of melatonin on expression of NGF in rats with spinal cord injury at early stage

Aim:To investigate the potential mechanism of melatonin(MT) against spinal cord injury(SCI) by detecting the levels of nerve growth factor(NGF) at early stage of SCI in rats.Methods:A total of 60 SD rats were divided into 3 groups randomly:rats in SCI group and MT group were to make the SCI model by using modified Allen's WD method at T12 level,and receive intraperitoneal injection of MT or dehydrated alcohol,respectively;sham group was for laminectomy only.12 h later,the function of the spinal cord was assessed by Basso Beattie Bresnahan locomotor rating scale(BBB scale),then the blood samples were taken to measure the serum levels of NGF,and the spinal cord was taken,histological examination was undertaken using HE,and NGF protein and mRNA were detected by immunohistochemical SP staining method and RT-PCR,respectively.Results:Severe lower limbs neurological dysfunction was observed in MT group and model group,but the difference between them in BBB scale had no statistical difference(P0.05).The histopathological changes of MT group were improved compared with model group.The differences in NGF mRNA and protein expressions in spinal cord tissues,and NGF protein in serum were significant among the 3 groups(F=336.819,321.762 and 122.707,P0.001);sham group had the lowest level,and MT group had the highest level(P0.01).Conclusion:MT could be used for SCI treatment based on its enhancement of NGF expression.