褪黑素对大鼠脊髓损伤早期NGF、NGF mRNA、MDA、SOD水平的影响

发布时间：2018-05-12 20:51

本文选题：脊髓损伤 + 褪黑素　；参考：《郑州大学》2012年硕士论文

【摘要】：研究背景与目的脊髓损伤(spinal cord injury, SCI)是一种严重而常见的中枢神经系统损伤,它多由创伤和疾病等原因所引发,常导致患者出现严重的运动及感觉功能障碍。脊髓原发机械损伤后会引起一系列级联式的病理变化,主要包括了局部微循环障碍、氧化应激、中性粒细胞侵润、细胞坏死和凋亡等,而SCI往往又是全身多发创伤的一部分,患者病情常常复杂而严重,这就给治疗时药物的选择造提出了很高的要求。目前治疗SCI疗效确切的药物并不多,且大多都被证实存在严重的副作用,这就促使我们积极寻找新的药物来治疗SCI。过去的许多研究已证实,褪黑素(melatonin, MT)对脊髓损伤有显著的治疗作用,但对其作用机制的研究还不完善。材料与方法 60只成年雄性Sprague-Dawley (SD)大鼠随机分为3组：脊髓损伤组(A组)、褪黑素治疗组(B组)、假手术组(Sham组),每组20只。A、B两组以改良的Allen's weight drop(WD)法(打击量50gcf)建立脊髓T12水平损伤模型,Sham组仅行椎板切除术不损伤脊髓。B组于术后10min按体重腹腔注射100mg/kg的MT,A组则按体重腹腔注射等体积的无水乙醇(MT的溶剂)。术后12h对各组大鼠进行神经功能评分后处死,取血液及脊髓标本检测NGF、MDA、SOD含量及NGF mRNA表达水平,并从各组中随机选取8例脊髓标本应用HE染色法观察其一般病理变化,,免疫组化SP法观察其内NGF的表达特点。统计资料采用SPSS17.0统计分析软件进行处理,计量资料以x±s表示,多组间比较采用单因素方差分析(ANOVA),各组方差具有齐性时,组间两两比较采用最小有意义差异t(LSD-t)检验,各组方差不齐时,采用Tamhane's T2检验。取α=0.05为显著性检验水准。结果 1.术后12h,大鼠脊髓内NGF mRNA表达水平和血清中NGF含量各组相较,褪黑素治疗组最高、脊髓损伤组次之、假手术组最低,其差异具有统计学意义(P0.01)： 2.血清中MDA含量比较,脊髓损伤组最高(P0.01)、褪黑素治疗组和假手术组之间的差异不具有统计学意义(P0.05)； 3.血清中SOD活性从高到低依次为假手术组、褪黑素治疗组、脊髓损伤组,各组差异具有统计学意义(P0.01)； 4.脊髓损伤及褪黑素治疗组大鼠于术后均出现了严重的下肢神经功能障碍,两组的BBB运动功能评分差异无统计学意义(P0.05)。 5.病理学观察表明,褪黑素可减轻脊髓损伤早期的病理变化并能提高损伤处脊髓前角及其周围白质内NGF的表达水平(P0.01)。结论 1.褪黑素可通过提高大鼠体内神经生长因子的表达水平和抑制脂质过氧化反应治疗大鼠脊髓损伤。 2.褪黑素可保护大鼠体内SOD的活力,间接地抑制脂质过氧化反应。 3.按体重腹腔注射l00mg/kg的褪黑素,虽可减轻脊髓损伤早期的病理变化但不能改善大鼠后肢的运动功能障碍。
[Abstract]:Research background and purpose Spinal cord injury (cord injury, SCI) is a serious and common injury to the central nervous system. It is caused by trauma and disease and often leads to severe motor and sensory dysfunction. Spinal cord primary mechanical injury may cause a series of cascade pathological changes, including local microcirculation disorder, oxidative stress, neutrophil infiltration, necrosis and apoptosis, etc. SCI is often a part of multiple trauma. The patient's condition is often complex and serious, which puts forward high requirements for drug selection. At present, there are few effective drugs for SCI, and most of them have been proved to have serious side effects, which urges us to actively seek new drugs to treat SCI. Many previous studies have confirmed that melatonin (MTM) has a significant therapeutic effect on spinal cord injury, but the mechanism of its action is not perfect. Materials and methods Sixty adult male Sprague-Dawley rats were randomly divided into three groups: spinal cord injury group (group A), melatonin treatment group (group B) and sham group (group B). Model sham group only underwent laminectomy without spinal cord injury. Group B received intraperitoneal injection of 100mg/kg according to body weight after 10min. The rats in each group were killed 12 hours after operation. The blood and spinal cord specimens were taken to detect the content of NGF mRNA and the content of SOD. Eight cases of spinal cord specimens were randomly selected from each group to observe the general pathological changes by HE staining and immunohistochemical SP method to observe the expression of NGF in the spinal cord. The statistical data were processed by SPSS17.0 statistical analysis software, the measurement data were expressed as x 卤s, and the single factor analysis of variance (ANOVAN) was used in the multigroup comparison. When the variance of each group was homogeneous, the least significant difference between the two groups was used to test. Tamhane's T2 test was used when the variance of each group was not equal. A 0.05 was taken as the significant test level. Result 1. At 12 hours after operation, the expression of NGF mRNA in spinal cord and the content of NGF in serum of rats were the highest in melatonin treatment group, followed by spinal cord injury group and sham operation group. The difference was statistically significant (P 0.01). 2. The MDA content in serum was the highest in the spinal cord injury group (P 0.01), but there was no significant difference between the melatonin treatment group and the sham operation group (P 0.05). 3. The activities of SOD in serum from high to low were sham-operation group, melatonin treatment group and spinal cord injury group. 4. The rats in spinal cord injury and melatonin treatment group had severe lower extremity neurological dysfunction after operation. There was no significant difference in BBB motor function score between the two groups (P 0.05). 5. Pathological observation showed that melatonin could attenuate the early pathological changes of spinal cord injury and increase the expression level of NGF in the anterior horn of spinal cord and its surrounding white matter. Conclusion 1. Melatonin can improve the expression of nerve growth factor and inhibit lipid peroxidation in the treatment of spinal cord injury in rats. 2. Melatonin can protect the activity of SOD and indirectly inhibit lipid peroxidation in rats. 3. Intraperitoneal injection of melatonin (l00mg/kg) according to body weight could attenuate the early pathological changes of spinal cord injury but could not improve the motor dysfunction of hind limbs in rats.
【学位授予单位】：郑州大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R651.2;R-332

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