Calderó J, Casanovas A, Sorribas A, Esquerda J E
Universitat de Barcelona, Estudi General de Lleida, Facultat de Medicina, Departament de Ciències Mèdiques Bàsiques, Catalonia, Spain.
Neuroscience. 1992;48(2):449-61. doi: 10.1016/0306-4522(92)90504-u.
Using light and electron microscopy, a study has been made of the changes of calcitonin gene-related peptide-like immunoreactivity in rat lumbar spinal cord motoneurons during cell body response to sciatic nerve injury. At light microscopy level, calcitonin gene-related peptide-like immunoreactivity was evaluated using an indirect immunofluorescence technique combined with Fast Blue retrograde tracing and a peroxidase-antiperoxidase procedure. The calcitonin gene-related peptide changes to sciatic nerve transection and crushing were compared. Calcitonin gene-related peptide-like immunoreactivity was transiently increased after the peripheral nerve lesion, but the response was sustained for a longer period when the peripheral nerve was transected and nerve regeneration prevented. The first changes in calcitonin gene-related peptide-like immunoreactivity were detected four days after nerve crush or transection. In animal spinal cords to which nerve crush had been applied, the maximal enhancement of immunoreactivity was found 11 days after lesion. This was followed by a gradual decline, normal levels being attained 45 days after nerve crushing. When the nerve was transected, the response was similar, but the maximal calcitonin gene-related peptide-like immunoreactivity was maintained over a period of between 11 and 30 days. As with crushing, an important decrease was observed after 45 days. The ultrastructural compartmentation of calcitonin gene-related peptide-like immunoreactivity was studied using either peroxidase-antiperoxidase method or immunogold labelling. Calcitonin gene-related peptide-like immuno-reactivity was located in restricted sacs of the Golgi complex, multivesicular bodies, small vesicles and tubulo-vesicular structures. Large, strongly labelled vesicles resembling secretory granules were also observed in neuronal bodies. Our results reveal that the increase of calcitonin gene-related peptide in motoneurons is a relevant change the cell body undergoes in response to peripheral injury. The ultrastructural location of the peptide distribution suggests specific compartmentation on tubulo-vesicular structures connected with the Golgi complex which form a network in the neuronal cytoplasm. The distribution pattern observed may be related to the sorting and delivery of calcitonin gene-related peptide to secretory vesicles.
利用光学显微镜和电子显微镜，对大鼠腰段脊髓运动神经元在胞体对坐骨神经损伤的反应过程中降钙素基因相关肽样免疫反应性的变化进行了研究。在光学显微镜水平，采用间接免疫荧光技术结合快蓝逆行追踪和过氧化物酶-抗过氧化物酶方法评估降钙素基因相关肽样免疫反应性。比较了降钙素基因相关肽对坐骨神经横断和挤压的变化。周围神经损伤后，降钙素基因相关肽样免疫反应性短暂增加，但当周围神经横断并阻止神经再生时，反应持续更长时间。神经挤压或横断后四天检测到降钙素基因相关肽样免疫反应性的首次变化。在施加神经挤压的动物脊髓中，损伤后11天发现免疫反应性最大增强。随后逐渐下降，神经挤压后45天达到正常水平。当神经横断时，反应相似，但最大降钙素基因相关肽样免疫反应性在11至30天内维持。与挤压一样，45天后观察到显著下降。使用过氧化物酶-抗过氧化物酶方法或免疫金标记研究降钙素基因相关肽样免疫反应性的超微结构分区。降钙素基因相关肽样免疫反应性位于高尔基体复合体的受限囊泡、多泡体、小泡和管状泡状结构中。在神经元胞体中也观察到类似分泌颗粒的大的、强染色的囊泡。我们的结果表明，运动神经元中降钙素基因相关肽的增加是胞体对外周损伤所经历的一种相关变化。肽分布的超微结构定位表明在与高尔基体复合体相连的管状泡状结构上有特定的分区，这些结构在神经元细胞质中形成网络。观察到的分布模式可能与降钙素基因相关肽向分泌囊泡的分选和运输有关。
