褪黑素对大鼠脊髓损伤后iNOS表达的影响

目的：探讨褪黑素对大鼠脊髓损伤后诱生型一氧化氮合酶（iNOS）表达的影响。方法：采用改良Allen’S撞击法制备脊髓损伤模型；成年SD大鼠110只随机分为假损伤组、损伤组和药物治疗组3组，其中损伤组和药物治疗组各50只，分5个时间点（8小时、24小时、72小时、7天、14天）处死；假损伤组10只，于手术后14天处死，采用HE染色和免疫组化检测脊髓损伤后脊髓组织中iNOS蛋白的表达。结果：与损伤组比较，药物治疗组大鼠损伤后脊髓组织iNOS表达明显降低，差异有统计学意义（P〈0．05）。结论：褪黑素可通过抑制iNOS蛋白表达对大鼠脊髓损伤起保护作用。

The Influence of Melatonin on the Expression of iNOS upon Rat Spinal Cord Injury

Objective ： To investigate the influence of Melatonin on the induction of inducible nitric oxide synthase （iNOS） expression in spinal cord upon spinal cord injury （SCI） in rats. Methods：SCI model was reproduced according to Allen＇s method with modification. One hundred and ten adult SD rats were randomly divided into three groups ： sham injury group （ n = 10 ） , the spinal cord injured group （ n =50）, and SCI with melatonin treatment group （ n =50）. For the SCI groups with or without melatonin treatment, rats were killed at different time （8h, 24h, 72h, 7d, 14d）. And rats of sham injury group were killed at 14d post SCI operation. HE staining and Immunohistochemistry method were employed to detect iNOS expression in spinal cord. Results ： Melatonin treatment significantly reduces the induction of iNOS expression in spinal cord of rats subjected to SCI operation （ P 〈 0.05 or 0.01 ）. Conclusion：The result suggests that melatonin may exert protective effect on spinal cord injury, through inhibiting the induction of iNOS expression.