鸟核苷酸调节蛋白在大鼠脑和脊髓内免疫组织化学定位

IMMUNOHISTOCHEMICAL LOCALIZATION OF GUANINE NUCLEOTIDE BINDING REGULATORY PROTEIN IN BRAIN AND SPINAL CORD OF RAT

本研究应用兔抗鸟核苷酸调节蛋白α_0亚单位(简称α_0)多克隆血清(抗体),采用免疫组织化学方法对大鼠脑和脊髓内一些结构中的α_0作了定位观察.发现α_0样免疫反应性(α_0-Li)在大鼠脑内的分布比较广泛,各脑区表现出分布不均,神经网织中呈高密度,神经元核周质缺乏或其少,α_0-Li主要位于胞体膜及其突起上.最强的α_0-Li见于黑质(网织部),脚间核及缰—脚间束,海马多形细胞层,辐射层和脊髓胶状质;中度染色者有:大脑皮质、小脑皮质及海马的分子层,缰核,尾壳复合体,中脑导水管周围灰质,上丘灰质,延髓三叉神经脊束及延髓橄榄小脑束,丘脑和下丘脑中线核群。但隔核,苍白球,红核,脊髓中央管周围灰质α_0-Li相对较弱.另外,发现在中脑导水管周围灰质、黑质、中脑网状结构、内侧膝状体及斜方体核区内一些神经元核周质及其突起上,存在有α_0-Li.AChE染色证明,0在一些α_0—Li阳性区域:大脑皮质分子层,海马,延髓三叉神经脊束及脊髓胶状质等,也富含AChE阳性(胆碱能?)神经末梢.结果提示,脑内G_0蛋白的α_0亚单位在膜信息传递中可能与胆碱能神经成分有一定关系。

The subunit α_0 of guanine nucleotide- binding protein, in the areas of rat brain and spinal cord was localized by immunohistochemical methods. It was found that in the rat brain, specific α_0-like immunoreactivity(α_0-Li) displayed regional heterogeneity, a high density of α_0-Li revealed in neuropil, and somatic membranes as well as the neuronal processes.Most intense α_0-Li can be seen in substantia nigra(pars reticulata), interpcduncular nucleus, habenulo-interpeduncular tract, strata oriens and radiatum of the hippocampus, and substantia gelatinosa of the spinal cord. There are also areas of moderate staining ie: the molecular layer of cerebral and cerebellar cortex, habenula, caudate-putamen complexes, the midline nuclei of thalamus and hypothalamus, periaqueductal grey, grey layers of superior colliculus, the olivo-cerebellar tract and the spinal tract of the trigeminal nerve as well. By contrast, the immunoreactvity of α_0 in septal nuclei, globus pallidus, red nucleus, and the regions adjacent canalis centralis of the spinal cord showed much weaker. In addition, on the membranes and the processes of the neuronal cell bodies in the periaqueductal grey, substantia nigra, reticular formation, medial geniculate body and the nucleus of the trapezoid body were α_0-Li positive.The results of AChE staining revealed that the AChE-positivc nerve terminals was coinsident with the presence of α_0-Li in the following regions. For instance: the molecular layer of cerebral cortex, hippocampus, spinal tract of the trigminal nerve, and substantia gelatinosa of the spinal cord, where both the α_0-Li and the AChE activity were positive. It is suggested that α_0 subunit of Go-protein in brain might play roles in membrane signal transduction, and might have some relationship with cholinergic nerve.