摘要
为探讨周围支切断对DRG神经元BDNF ,NT 3及其mRNA表达的影响 ,将 5只成年猫麻醉后暴露双侧L7DRG ,于一侧距DRG 1cm处切断外周支 ,另一侧为对照。动物存活 3d后取两侧L7DRG制作 2 0 μm厚冷冻切片。分别用BDNF、NT 3抗体及BDNFcRNA ,NT 3cRNA探针 (地高辛末端标记 )行ABC免疫组化和原位杂交染色。观察BDNF ,NT 3及其mRNA的阳性产物部位 ,计数恒定面积内BDNF ,NT 3及其mRNA的阳性神经元数量。结果BDNF及mRNA的阳性细胞主要是DRG胞体偏小的神经元 (135 7μm)。而NT 3及mRNA的阳性细胞则主要是胞体偏大的神经元 (5 710 0 μm)。恒定面积内BDNF及其mRNA和NT 3及其mRNA的阳性神经元数量实验侧分别是 16.4± 0 .7,11.1± 1.4和 2 4 .5± 2 .1,2 2 .8± 3.2 ,而对照侧则分别是 10 .3± 1.9,6.1± 0 .9和 12 .5± 2 .7,15 .3± 4 .1。比较两侧BDNF、NT 3及其mRNA的阳性神经元数量均有显著差异 (P <0 .0 5 )。表明周围支切断可致DRGBDNF ,NT 3的表达明显增多。提示BDNF ,NT
After anesthesia fi ve cats were exposed bilaterally on L 7 DRG, a unilateral peripheral axotomy was performed on 1 cm away from L 7 DRG and the other side was used as the control. The animals were sacrificed and both sides of L 7 DRG were removed 3 days after operation. The DRG were sectioned into frozen slices (thickness 20 μm).By using immunohistochemical method and in situ hybridization techniqu e, the slices were stained by cRNA probe and antiserum of BDNF and NT 3. The po sitive neurons of BDNF and their mRNA in DRG were mainly small to medium in size (13~57 μm), while those of NT 3 were mainly large (57~100 μm). The numbers o f positive neurons of BDNF, BDNF mRNA and NT 3, NT 3 mRNA in operated side wer e 16.4±0.7, 11.1±1.4 and 24.5±2.1,22.8±3.2 respectively, while those of th e control side were 10.3±1.9,6.1±0.9 and 12.5±2.7,15.3±4.1 respectively. Compared with the numbers of positive neurons, there are apparent differences b etween the oprated side and the control ( P <0.05). The results showed that th e periperal axotomy upregulated the expression of BDNF and NT 3 in DRG neurons, and BDNF and NT 3 may play roles in initial reaction of ganglionic neurons to nerve injury.
基金
云南省自然科学基金资助项目 ( 99C0 0 0 6R)
