新生大鼠缺氧缺血脑损伤后神经可塑性相关蛋白的表达

Expression of Neurocan in the Brain of Rats after Neonatal Hypoxia-Ischemia Brain Damage

目的观察缺氧缺血性脑损伤（HIBD）后新生大鼠脑内神经蛋白聚糖（neurocan）表达的动态变化，探讨neurocan与脑神经可塑性改变的相互关系。方法7d龄SD大鼠随机分为假手术组和HIBD组，于脑缺氧缺血后1，4，7，14，28d取脑组织进行HE染色和免疫组化法观察组织病理变化及neurocan蛋白水平表达，以RT—PCR法检测其mRNA水平。结果假手术组neurocan的表达于术后7d达到高峰（P〈0．05），此后阳性表达逐渐减少；HIBD组术后4，7d的neurocan蛋白及mRNA表达均低于相应假手术组（P〈0．05），而至术后14，28d表达开始增高，均高于相应假手术组（P〈0．05）。结论新生大鼠HIBD后脑组织neurocan蛋白及其mRNA表达随着时间的推移而逐渐升高，提示HIBD后神经可塑性的抑制性因素调控的关键时期为损伤后2w内。

Objective To explore the expression of neuronal plasticity associated protein neurocan in the brain of rats after different time of neonatal hypoxia-ischemia brain damage（HIBD）. Methods 7 days neonate SD rats were first ligated the left carotid artery and put into the oxygen deficiency box with only 8 % oxygen for 2 hours. Then at 1,4,7,14 and 28 days after the operation,dissected the brain and pathology detection. The expression of neurocan was detected by reverse transcription-polymerase chain reaction （RT-PCR） and immunohistochemical method,respectively. Results The amount of neurocan reached a peak level after 7 days of the operation in sham-operated brains. Expression of neurocan in HIBD brains at 4,7 days after the operation was lower than that of sham-operated brains （P〈0. 05）,while was higher than that of sham-operated brains at 14 and 28 day after the operation （P〈0. 05）. Conclusion Neuronal plasticity was different with the progress of neonatal HIBD and the best time for nerve repair would be within two weeks.