神经生长因子对新生鼠缺氧缺血性脑损伤神经修复作用的研究

目的研究神经生长因子(NGF)对新生鼠缺氧缺血性脑损伤(HIBD)后,神经干细胞巢蛋白(nestin)及血管内皮生长因子(VEGF)表达的影响,探讨其神经修复作用机制。方法7日龄新生SD大鼠84只,建立HIBD模型后,随机分为假手术组、缺氧缺血组及NGF干预组各28只。神经生长因子干预组腹腔内注射NGF(6000U/kg/d),缺氧缺血组同步注射等量生理盐水。采用免疫组化法检测NGF对新生大鼠HIBD后不同时间内Nestin及VEGF表达的影响。结果缺氧缺血性脑损伤后12、24h,3、7、14d,NGF干预组在大脑皮质、海马和室旁区的Nestin表达高于缺氧缺血组(P<0.05),且高峰提前到3d。HIBD后即刻、3、12、24h及3d,NGF干预组在大脑皮质、海马区VEGF的表达高于缺氧缺血组(P<0.05),且高峰提前到3h。结论NGF对HIBD具有神经修复作用可能是通过上调nestin及VEGF的表达而实现的。

Neuro-protective effects of nerve growth factor on newborn rats with hypoxic-ischemic brain damage

Objective To study the effects of nerve growth factor(NGF)on the expressions of Nestin and vascular endothelial growth factor (VEGF) in the brain of the rats with hypoxic-ischemic brain damage (HIBD) and to study the neuro-protective effect of NGF. Methods Eighty four 7-day postnatal SD rats were randomly divided into 3 groups, sham operation (control) group (n=28), HIBD group (n=28) and NGF- treated groups (n=28). Immediately after hypoxic-ischemic (HI) insult, 6000U/(Kg.d) of NGF or same amount of normal saline was injected intra-peritoneally in NGF-treeded group or HIBD group and control group respectively once a day for 7 days. The expression of Nestin and VEGF in cerebral tissues was tested via immunohistochemical technique. Results The expression of Nestin in NGF-treated group was markedly higher in cortex, hippocampal and periventricular zone at 12 h, 24 h, 3 d and 7 d after HI insult than HIBD group (P<0.05), and this reached peak at day 3. The expression of VEGF in NGF-treated group increosed in cortex and hippocampal at 0 h, 3 h, 12 h, 24 h, 3 d after HI insult compared loith HIBD group (P<0.05), and the highest expression appeared at 3 hours. Conclusions The neuro-protective effect of NGF on the newborn rats with HIBD is related to the increased expression of Nestin and VEGF.