褪黑素对急性脊髓损伤大鼠血清及脊髓内神经生长因子表达的影响

目的研究褪黑素（MT）对脊髓损伤大鼠血清及脊髓内神经生长因子（NGF）表达水平的影响。方法84只健康成年雄性SD大鼠随机分为模型对照组（n=36）、模型MT组（n=36）及假手术组（n=12）。建立脊髓损伤模型后，模型对照组给予无水乙醇，模型MT组给予MT，均为腹腔注射。对比术后12h、3、5d大鼠血清及脊髓组织中NGF的表达及Tarlov评分。结果术后12h模型对照组及模型MT组Tarlov评分显著低于假手术组（P〈0．05）。模型MT组TarlOV评分稍高于模型对照组，但差异无统计学意义（P〉0．05）。术后3、5d模型MT组Tarlov评分均显著高于模型对照组（P〈0．05或P〈0．01）。术后12h、3、5d模型对照组和模型MT组血清NGF水平、脊髓组织NGF蛋白及NGFmRNA水平均较假手术组显著上升，模型MT组则显著高于模型对照组（P〈0．05或P〈0．01）。结论MT通过调高脊髓损伤大鼠体内NGF的表达起到减轻神经细胞损伤、促进神经细胞再生和神经功能恢复作用。

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.