Effect of melatonin on NGF expression in serum and spinal cord in rats with acute spinal cord injury

Objective To study the effect of melatonin(MT) on nerve growth factor(NGF) expression in serum and spinal cord in rats with acute spinal cord injury.Methods 84 healthy adult male SD rats had been randomly divided into the model control group(n = 36),model MT group(n = 36) and sham-operated group(n = 12).Spinal cord injury model was established,model control group was treated with anhydrous ethanol,model MT group was given MT injection.12 h,3,5 d after operation,serum and spinal cord tissue NGF expression and Tarlov scores were compared among the three groups.Results 12 h after operation,the scores of Tarlov in the model control group and model MT group were significantly lower than the sham-operated group(P 0.05),the model MT group Tarlov score was slightly higher than the model control group,but there was no statistically significant(P 0.05).3 and 5 d after operation,Tarlov scores in model MT group were significantly higher than those in the model control group(P 0.05 or P 0.01).12 h,3,5 d after operation,serum NGF,spinal cord tissue NGF protein and NGF mRNA levels in model group and model MT group significantly increased than those in the sham-operated group,those in the model MT group were higher than in the model control group(P 0.05 or P 0.01).Conclusion MT reduces nerve cell damages,promote regeneration of nerve cells and nerve function recovery in rats by increasing NGF expression with spinal cord injury in vivo.