缺氧新生鼠胼胝体神经元-胶质细胞抗原2、胶质纤维酸性蛋白表达观察

Expression change of NG2 and GFAP in the corpus callosum of neonatal rats under hypoxia

目的观察缺氧新生大鼠胼胝体神经元-胶质细胞抗原2(NG2)、胶质纤维酸性蛋白(GFAP)的表达变化。方法新生3 d的SD大鼠36只随机分为对照组、低浓度组(6%氧)、高浓度组(8%氧)各12只。对照组新生鼠不做任何处理。低、高浓度组制作缺血缺氧(HI)损伤模型。分别于造模2、3、4周时各组取4只大鼠,处死后断头取脑,切大鼠氧损伤侧及对照侧组织切片,采用免疫荧光染色法检测大鼠氧损伤侧及对照侧脑组织NG2、GFAP表达。造模4周时观察各组大鼠存活情况。结果与氧损伤对照侧比较,造模2、3周时低、高浓度组脑组织NG2阳性细胞数均增多(P <0. 05);与低浓度组氧损伤侧比较,造模2周时高浓度组脑组织NG2阳性细胞数增多(P <0. 05)。与氧损伤对照侧比较,造模2、3、4周时低、高浓度组脑组织胼胝体GFAP阳性细胞数均增多(P均<0. 05);与低浓度组氧损伤侧比较,造模2、3周时高浓度组脑组织胼胝体GFAP阳性细胞数均增多(P <0. 05)。造模4周时,低浓度组、高浓度组、对照组大鼠分别存活9、10、12只。与低浓度组比较,对照组、高浓度组大鼠存活数目多。结论 :缺氧可导致新生大鼠胼胝体NG2、GFAP表达升高。6%、8%氧浓度均可导致新生大鼠胼胝体NG2、GFAP表达升高,且8%氧浓度作用更强。

Objective To observe the expression changes of neuron-glial antigen 2(NG2)and glial fibrillary acidic protein(GFAP)in the corpus callosum of neonatal rats under different conditions of hypoxia-ischemia(HI)injury.Methods Thirty-six 3-day-old neonatal SD rats were randomly divided into 3 groups:the control group,low-concentration(6%oxygen)and high-concentration(8%oxygen)groups.Neonatal rats in the control group were not treated,and we established the HI injury models in the low-concentration and high-concentration groups.Contralateral and ipsilateral cryosections were made at 2,3 and 4 weeks,respectively.Immunofluorescence staining was applied to assess the changes of NG2 and GFAP in different conditions of hypoxia.The survival rats in each group were observed at 4 weeks after injury.Results The NG2 positive cells in the ipsilateral corpus callosum significantly increased as compared with those in the contralateral corpus callosum at 2 and 3 weeks after HI(P<0.05),but no difference between them at 4 week after HI.The number of NG2 positive cells in the ipsilateral corpus callosum was higher in the high-concentration group than that in the low-concentration group(P<0.05).The GFAP positive cells increased dramatically as compared with those in the contralateral corpus callosum of the low-concentration and high-concentration groups at 2,3 and 4 weeks after injury(P<0.05).The number of GFAP positive cells in the low-concentration group was higher than that of the high-concentration group at 2 and 3 weeks after injury(P<0.05).At 4 weeks,9,10 and 12 rats survived in the low-concentration group,high-concentration group,and control group,respectively.The survival rats in the low-concentration group was lower than that in the high-concentration group and control group.Conclusions Hypoxia can increase the expression of NG2 and GFAP in the corpus callosum of neonatal rats.Both 6%and 8%oxygen-induced injury can increase NG2 and GFAP expression in the corpus callosum of neonatal rats,and 8%oxygen has stronger effect.