[H-3]CORTICOSTERONE BINDING IN THE CAUDATE-PUTAMEN
[H-3]CORTICOSTERONE BINDING IN THE CAUDATE-PUTAMEN
复制标题
DOI：
10.1016/0006-8993(83)90227-5
复制
发表时间：
1983-01-01
期刊：
影响因子：
2.9
通讯作者：
TURNER, BB
中科院分区：
文献类型：
--
作者：
DEFIORE, CH;TURNER, BB
放射自显影数据表明皮质酮在尾壳核中几乎没有特异性结合。据报道，长期糖皮质激素治疗会改变尾壳核内的某些生化参数，包括高亲和力胆碱摄取，可以通过生化方法检测肾上腺切除大鼠尾壳核中的糖皮质激素受体。测定了尾壳核细胞质中特异性[3H]皮质酮结合的量以及该脑区域的细胞核在体内保留[3H]皮质酮的能力。结果表明，肾上腺切除后72小时，尾壳核具有海马最大结合能力的56%（205.+-.11 vs. 361.+-.19fmol/mg蛋白质）。两种组织中[3H]皮质酮的表观Kd 没有显着差异。尾壳核的胞质结合能力与小脑相似，小脑是一个在放射自显影研究中也未能证明糖皮质激素显着保留的大脑区域。当肾上腺切除后较短的时间段（12小时）测量细胞质结合时，在海马和尾壳核的结合能力之间没有观察到差异。在使用[3H]皮质酮作为配体的竞争实验中，尾壳核和海马之间没有发现8种类固醇的相对亲和力存在差异；获得的相对亲和力的顺序与其他组织中经典糖皮质激素受体的报道非常一致。通过尾静脉向大鼠注射[3H]皮质酮，剂量为36 nmol/kg，计算出的量足以使超过一半的核位点饱和。从这些大鼠的尾壳核纯化的细胞核显示出海马细胞核中存在的约 40% 的放射性（1158.+-.24 对比 2988.+-.320 fmol/mg DNA）。在尾壳核和海马体中，相对于整个组织，放射性在细胞核中集中数倍；在小脑或下丘脑中没有观察到这种程度的核集中。特定的[3H]皮质酮结合蛋白存在于大鼠的尾壳核中，它们是功能性糖皮质激素受体，能够进行核转位。尾壳核与放射自显影照片上主要未标记的其他大脑区域的区别不在于其胞质结合位点的数量，而在于其细胞核能够浓缩[3H]皮质酮的程度。
Autoradiographic data indicate little specific binding of corticosterone in the caudate-putamen. Chronic glucocorticoid treatment was reported to alter certain biochemical parameters within the caudate-putamen, including high-affinity choline uptake could glucocorticoid receptors in the caudate-putamen of adrenalectomized rats be detected by a biochemical approach. The amount of specific [3H]corticosterone binding in cytosols from the caudate-putamen and the ability of nuclei in this brain region to retain [3H]corticosterone in vivo was determined. Results indicated that 72 h post-adrenalectomy, the caudate-putamen has 56% of the maximal binding capacity of the hippocampus (205 .+-. 11 vs. 361 .+-. 19 fmol/mg protein). The apparent Kd of [3H]corticosterone in the 2 tissues did not differ substantially. The cytosolic binding capacity of the caudate-putamen was similar to that of the cerebellum, a brain region which also fails to demonstrate marked retention of glucocorticoids in autoradiographic studies. When cytosol binding was measured at a shorter time period after adrenalectomy (12 h), no differences were observed between the binding capacities of the hippocampus and the caudate-putamen. In competition experiments using [3H]corticosterone as ligand, no differences between the caudate-putamen and the hippocampus were found in the relative affinities of any of 8 steroids; the order of relative affinities obtained was in good agreement with those reported for the classical glucocorticoid receptor in other tissues. Rats were injected via the tail vein with [3H]corticosterone, 36 nmol/kg, an amount calculated to saturate more than half the nuclear sites. Nuclei purified from the caudate-putamen of these rats demonstrated about 40% of the radioactivity present in hippocampal nuclei (1158 .+-. 24 vs. 2988 .+-. 320 fmol/mg DNA). In the caudate-putamen and hippocampus, radioactivity was concentrated several-fold in the cell nuclei relative to whole tissue; this degree of nuclear concentration was not seen in the cerebellum or hypothalamus. Specific [3H]corticosterone binding proteins exist in the caudate-putamen of rats and they are functional glucocorticoid receptors, capable of nuclear translocation. The caudate-putamen is distinguished from other brain regions which appear predominantly unlabeled on autoradiographs, not in its number of cytosol binding sites, but by the degree to which its cell nuclei are able to concentrate [3H]corticosterone.