坐骨神经切断对大鼠脊髓背根节NGF和BDNF表达的影响

目的:探讨切断坐骨神经对成年SD大鼠背根节NGF和BDNF表达的影响。方法:用10只成年SD大鼠,切断一侧坐骨神经,术后存活3d,取手术侧和非手术侧的背根节,用NGF和BDNF的cRNA探针进行常规原位杂交染色。观察该两因子mRNA阳性反应产物在背根节的分布和变化。用计算机图像分析系统,测量坐骨神经切断后手术侧和非手术侧的100个阳性反应神经元NGF和BDNF的mRNA阳性反应神经元的平均灰度,以反映NGF和BDNF相对含量。结果:在背根节中可见NGF和BDNF的mRNA的阳性神经元,阳性反应产物星兰色位于细胞质。相比之下,呈NGF的mRNA阳性反应神经元的数量较少。手术侧NGF和BDNF的平均灰度值(82.3±3.4和80.2±5.4)较非手术侧的平均灰度(101.3±6.5和109.5±2.4)降低,表明手术侧NGF和BDNF的mRNA较非手术侧者明显增加,p<0.01。结论:提示坐骨神经切断可促进背根节NGF和BDNF的mRNA的表达增加,NGF和BDNF可能在周围神经损伤后的修复反应中具有重要作用。

Effects of sciatic nerve amputation on the expression of NGF and BDNF in the dorsal root ganglion of spinal cord in rats

Objective: To explore the effects of sciatic nerve amputation on the expression of NGF and BDNF in adult rats. Methods: The sciatic nerve on one side was amputated in ten rats. They were sacrificed after surviving three days. The normal in situ hybridization staining was performed on the dorsal root ganglions (DRGs) from the operation side and the intact side using BDNF and NGF cRNA probes. The distribution and changes of the positive reaction neurons of NGF mRNA and BDNF mRNA were observed and the average grey grade that can reflect the relative content of NGF and BDNF in neurons was measured. Results: The postitive neurons of BDNF were more than that of NGF. The average value of grey grade of NGF and BDNF on operation side decreased compared with that on in- tact side, which indicated that NCF mRNA and BDNF mRNA on operation side increased (P< 0.01). Condusioa: Sciatic never amputation can promote the expression of NCF mRNA and BDNF mRNA. NCF and BDNF may play an important role in nerve recovery response following peripheral nerve injury.