中文摘要：

目的探讨细菌脂多糖（LPS）诱导活性小胶质细胞（MG）激活对少突胶质前体（preOLs）毒性作用。方法 2日龄SD大鼠随机分为假手术组和脑室周围白质软化（PVL）模型组,每组24只。脑立体定位仪下对PVL组新生大鼠经脑室注入LPS1μg/g,建立感染型PVL新生大鼠动物模型;对假手术组新生大鼠经脑室注入相同体积的无菌PBS。于造模后第5天处死取脑,分别进行光镜下脑白质病理评估、硝酸还原法检测NO含量、还原比色法检测O2-含量、免疫组织化学染色检测过氧亚硝酸盐（ONOO^-）含量以及OL前体的存活率。结果与假手术组相比,LPS诱导可引起新生大鼠的脑白质严重损伤（Z=7.498,P=0.000）,脑内O2^-含量（42.822±3.600比187.717±8.566,t=26.907,P=0.000）明显增加,NO含量[（1.097±0.079）μmol/gprot比（2.878±0.183）μmol/gprot,t=34.728,P=0.000]、ONOO^-含量[（0.000±0.000）%比（11.000±1.732）%]均显著增加,脑白质内O4阳性OL前体[（11.513±0.775）%比（3.353±0.442）%,t=16.013,P=0.000]大量减少。结论从体内确认LPS诱导OL前体的死亡通路,是通过LPS诱导MG激活,促使生成大量NO、O2^-和ONOO^-,作用于OL前体,导致OL前体的死亡。

英文摘要：

Objective To explore the toxicity of lipopolysaccharide（LPS）-induced activated-microglia（MG） to preoligodendrocytes（preOLs） in neonatal rats with infective-type periventricular leukomalacia（PVL）.Methods Forty-eight 2-day-old SD neonatal rats were randomly divided into two groups（sham group and PVL group）,24 rats in each group.Under brain stereo-positioner,LPS 1 μg/g was injected into the lateral ventricle of neonatal rats in the PVL group,and similar volume of sterile PBS was injected into the lateral ventricle of neonatal rats in the sham group.Pathological assessment was made under light microscope,the concentration of nitric oxide（NO） was measured by nitric acid-deoxidize colorimetry,the generated levels of（O2^-） was determined by deoxidize colorimetry,and the level of peroxynitrite ONOO^-and the survival rate of preOLs determined by immunocytochemistry for all neonatal rats in both groups 5 days after LPS injection.Results Compared to the rats of the sham group,there were obvious injuries of periventricular white matter（16.5 vs.48.5,Z = 7.498,P = 0.000）,massive loss of positive O4-labelled preOLs [（11.513 ± 0.775） % vs.（3.353 ± 0.442） %,t = 16.013,P = 0.000],and significantly higher levels of NO [（1.097 ± 0.079） μmol/g prot vs.（2.878 ± 0.183） μmol/g prot,t = 34.728,P = 0.000],ONOO^-[（0.000 ± 0.000） % vs.（11.000 ± 1.732） %] and O2^-[（42.822 ± 3.600） vs.（187.717 ± 8.566）,t = 26.907,P = 0.000] were found in neonatal rats of the PVL group.Conclusions It is validated in vivo that LPS activated MG to overproduce NO,O2^-and ONOO^-,which finally lead to the death of preOLs.