许旺细胞源神经营养因子在大鼠腰髓中的表达

背景许旺细胞能分泌多种营养因子,有保护和营养神经元的作用,并对神经损伤后的修复起促进作用.目的观察正常成年大鼠和不同胎龄鼠及幼鼠腰髓组织中许旺细胞源神经营养因子的表达,及其对脊髓不同发育时期的作用.设计对照实验,动物实验.材料实验于2003-09于南华大学动物实验室完成,采用Wister大鼠30只,雌雄不限,体质量为150～300g,由南华大学动物实验室提供.干预①取材和切片取体质量180～220 g,成熟期为4～6周正常成年大鼠腰髓和背根神经节,继而行后固定.共8只雌鼠受孕,取不同孕龄母鼠中的胎鼠及幼鼠腰髓组织,分别行冰冻切片.②免疫组化染色以抗许旺细胞源神经营养蛋白抗体作为一抗,行卵白素-生物素过氧化物酶复合物免疫组化染色,观察染色部位的灰度,通过电脑上扫描计算染色深度得出半定量值,分析许旺细胞源神经营养因子在腰髓的表达.主要观察指标①正常腰髓免疫组化染色结果.②生长发育的腰髓免疫组化染色结果.结果共8只雌鼠受孕,实验样本均取自8只受孕雌鼠的胎鼠及所产幼鼠.①正常腰髓免疫组化染色结果许旺细胞源神经营养因子在成年大鼠腰髓的整个白质和灰质后角Ⅲ、Ⅳ、Ⅴ层有较低表达.②生长发育的腰髓免疫组化染色结果许旺细胞源神经营养因子在胎龄14d和胎龄15d开始有表达,胚胎时期表达先增高后下降,其中胎龄21 d最高.出生后许旺细胞源神经营养因子在腰髓中表达明显下降,其中第7和12d最高.结论许旺细胞源神经营养因子在成年大鼠腰髓及背根神经节有较低表达,在生长发育的腰髓中表达基本呈逐渐下降趋势.许旺细胞源神经营养因子对大鼠脊髓的发育可能起促进作用,此结果说明许旺细胞源神经营养因子在脊髓生长发育过程中,主要在胚胎发育时期起作用.

Expression of Schwann cell derived neurotrophic factor in developing lumbar spinal cord of rats

BACKGROUND: Schwann cell can excrete many neurotrophic factors,protect neuron, and be nutritious to neuron. It also can promote the recover of injury of nerve.OBJECTIVE: To observe the expression of Schwann cell derived neurotrophic factor(SDNF) in developing lumber spinal cord of normal adult and different embryo rats as well as immature rats, and the effect on spinal cord in various developing period.DESIGN: Randomized and Controlled animal study.MATERIALS: The experiment was completed in the Animal Laboratory of Nanhua University in September 2003. Totally 30 Wister rats, in each gender,weighing 150-300 g, were selected from Animal Laboratory of Nanhua University.INTERVENTIONS: ① Selection and section: The normal lumbar spinal cord and dorsal root ganglia of normal adults rats with body mass in 180-220 g and 4-6 mature stages were fixed. Frozen sections were selected from 8 pregnant female rats including various embryol rats and immature rats. ② Immunohistochemical staining: Regarding protein antibody of SDNF as the first antibody,avidin-biotin peroxidase method was used to stain, the ash value was observed and the demi-quantitative value was worked out by scanning staining depth in order to analyze the expression of SDNF in lumbar spinal cord.MAIN OUTCOME MEASURES: ① Immunohistochemical staining of normal lumbar spinal cord; ② Immunohistochemical staining of developing lumbar spinal cord.RESULTS: Eight female rats were pregnant, and all samples were selected from the fetal rats and the immature rats. ① There appeared well-distributed SDNF, staining the whole white matter and Ⅲ, Ⅳ, Ⅴ stratum of the poster horn of gray matter of adult rats, and the dorsal root ganglia is much more intensively stained than lumber spinal cord. ② There was a inclination of early increase and late declination of SDNF immunoreactivity and the staining reaches a maximum at 21-day embryo, and then decreased at 7-day embryo and 12-day embryo after birth.CONCLUSION: There is lower expression of SDNF in lumber spinal cord of adult rats. But the expression of SDNF decreases gradually in the developing lumber spinal cord of rats. This means that SDNF may promote the development of spinal cord of embryo rats.