胶质细胞源性神经营养因子对比目鱼肌切除后相关运动神经元群降钙素基因相关肽表达的影响

目的：探讨鞘内注射胶质细胞源性神经营养因子(GDNF)对比目鱼肌(SOL)切除后相关运动神经元Mn群降钙素基因相关肽(CGRP)表达的影响。方法：应用霍乱毒素B亚单位结合胶体金(CB-Au)逆行标认神经元复合免疫细胞化学反应的非荧光双标法,显示标记SOL-Mn群CGRP样免疫反应(CGRP-LI)。结果：(1)与对照组相比,SOL切除后SOL-Mn群CGRP-LI强阳性Mn比率由正常的23．48%分别上升到68．8%(3d)、65．32% (10d)；此后逐步降低到11．3%(30d)。(2)SOL切除后,鞘内注射GDNF强阳性Mn比率可达70．91%(30d)。结论：鞘内注射GDNF可以显著提高靶肌肉切除后相关Mn群CGRP的表达,提示GDNF对运动神经元的部分神经营养作用可能是通过上调CGRP实现的。

Effect of glial cell line-derived neurotrophic factor on calcitonin gene related peptide expression in soleus motoneurons after soleus resection

Objective:To study the effect of Glial cell line-derived neurotrophic factor (GDNF) on the expression of calcitonin gene-related peptide (CGRP) in soleus moteoneuron pools after soleus resection.Methods:Double labeling of cholera toxin B subunit,colloidal gold (CB-Au) retrograde identification,and CGRP immunocyto chemistry were used to reveal the CGRP-like immunoreactivity (CGRP-LI).Results:Compared with control group,the proportion of the strongly positive CGRP-LI Mns in of SOL-Mn pools after soleus resection increased from 23.48% (control) to 68.8% (3 d) and 65.32% (10 d),respectively,then declined to 11.3% (30 d).The ratio of CGRP-LI strongly positive SOL-Mns increased to 70.91% (30 d) when GDNF was intrathecally adminis- tered afer soleus resection.Conclusion:GDNF can promote the expression of CGRP in SOL-Mn pool after soleus resection,which indicates that some of neurotrophic actions of GDNF are mediated through CGRP up-regulation.