新生豚鼠胆红素脑病时皮层及海马BDNF及其mRNA表达影响的实验研究

Study on the Expression of BDNF and BDNFmRNA in the Cerebral Cortex and Hippocampus in the Guinea Pig's Kernicterus Model

目的探讨胆红素脑病时BDNF及其mRNA在大脑皮层及海马的表达及其作用.方法应用免疫组化、原位杂交技术进行实验研究,镜下计数大脑皮层及海马区BDNF及BDNFmRNA阳性神经元细胞数、阳性神经元细胞平均灰度.结果注射胆红素后4 h组与对照组相比皮层BDNF的表达降低,海马BDNF的表达变化不明显;8 h组表达均较同剂量4 h组增加.与对照组相比注射胆红素后BDNFmRNA的表达4 h、8 h组呈持续增加,且8 h组BDNFmRNA表达高于4 h组,并与时间、剂量存在一定关系.结论在胆红素脑病早期皮层BDNF表达降低,海马变化不明显,随损伤时间及程度加重表达增高;BDNFmRNA在胆红素脑病早期表达即增快,随损伤时间及程度加重进一步增高;实验提示BDNF在胆红素脑病时可能发挥其神经元保护作用.

Objective To explore the expression and the possible meaning of BDNF and BDNFmRNA in the region of cerebral cortex and hippocampus. Methods Immunohistochemistry and in situ hybridization techniques were used in the experiment. The number of the positive - expression neurons was counted and the average gray level was measured in the region of cerebral cortex and hippocampus. Results Compared with the contral groups, the expression of BDNF in groups 4 h decreased in the region of cerebral cortex, no obvious change was found in hippocampus and the expression of BDNF in groups 8 h is higher than that in groups 4 h in the same dose while the expression of BDNFmRNA in both groups 4 h and groups 8 h all increased, the expression in groups 8 h are higher than that in groups 4 h and the change of the expression are associated with time and dose.Conclusion The expression of BDNF decreased in the initialed period of injury in the region of cerebral cortex and no obvious expression change was found in hippoeampus.That expression increased as the injury delayed and aggravated.The expression of BDNFmRNA also increased as the injury delayed and aggravated.This experiment indicated that BDNF could probably protect nerve cell in the kernicterus model.