Pannese Ennio, Procacci Patrizia
Institute of Histology, Embryology and Neurocytology, University of Milan, Milan, Italy.
J Neurocytol. 2002 Sep-Nov;31(8-9):755-63. doi: 10.1023/a:1025708132119.
Data on the presence of NGF receptors in the satellite cells of spinal ganglia are scanty and contradictory. In the present study we used immunocytochemistry to examine the distribution of these receptors in spinal ganglia of the adult rat by light and electron microscopy. We found that (1) all satellite cells were immmunoreactive to p75 and the mean density of gold particles (mean number per microm2) was significantly greater in the satellite cell sheath than in the nerve cell body; (2) numerous satellite cells were immunoreactive for trkA with a mean density of gold particles slightly greater in the satellite cell sheath than in the nerve cell body, although the difference was not statistically significant; (3) both p75 and trkA immunoreactivity were confined to the cytoplasm. We suggest that the p75 receptor may be involved in the NGF-induced outgrowth of slender projections from the nerve cell body surface. With regard to the trkA receptor, satellite cells might be supported trophically by NGF released from the neuron with which they are associated; alternatively, satellite cells might internalize NGF to constitute a reservoir for later release to the neuron.
关于脊髓神经节卫星细胞中神经生长因子（NGF）受体存在情况的数据稀少且相互矛盾。在本研究中，我们运用免疫细胞化学方法，通过光学显微镜和电子显微镜检查了成年大鼠脊髓神经节中这些受体的分布。我们发现：（1）所有卫星细胞对p75均呈免疫反应性，且卫星细胞鞘中金颗粒的平均密度（每平方微米的平均数）显著高于神经细胞体；（2）许多卫星细胞对trkA呈免疫反应性，卫星细胞鞘中金颗粒的平均密度略高于神经细胞体，尽管差异无统计学意义；（3）p75和trkA的免疫反应性均局限于细胞质。我们认为，p75受体可能参与了NGF诱导的从神经细胞体表面伸出细长突起的过程。关于trkA受体，卫星细胞可能从与其相关联的神经元释放的NGF中获得营养支持；或者，卫星细胞可能内化NGF以构成一个储备库，供日后释放给神经元。
