Zhai Q, Lai Z, Roos P, Nyberg F
Department of Pharmaceutical Biosciences, University of Uppsala, Sweden.
Acta Paediatr Suppl. 1994 Dec;406:92-5. doi: 10.1111/j.1651-2227.1994.tb13433.x.
The binding of 125I-labelled rat growth hormone (GH) to different areas in the brain was studied in male Sprague-Dawley rats. A high density of GH binding was found in the choroid plexus, hypothalamus, hippocampus, pituitary and spinal cord, whereas a lower binding density was observed in the cortex. Binding of the hormone to the various brain regions was age dependent. Binding was also dependent on time, pH and protein concentration. The binding affinity of the labelled hormone to choroid plexus was 4.3 per nmol/l and the binding capacity was 33.4 nmol/mg protein. The corresponding figures for binding of 125I-labelled GH to hypothalamus were 5.6 per nmol/l and 21.6 nmol/mg protein. By sodium dodecyl sulphate electrophoresis of the cross-linked hormone-receptor complexes, molecular weights of 60,000 and 61,000 were determined for the binding units in the choroid plexus and hypothalamus, respectively. It was further indicated that the binding unit for rat GH was distinct from that for prolactin.
在雄性斯普拉格-道利大鼠中研究了125I标记的大鼠生长激素（GH）与大脑不同区域的结合情况。在脉络丛、下丘脑、海马体、垂体和脊髓中发现了高密度的GH结合，而在皮质中观察到较低的结合密度。激素与各个脑区的结合具有年龄依赖性。结合还取决于时间、pH值和蛋白质浓度。标记激素与脉络丛的结合亲和力为每纳摩尔/升4.3，结合容量为每毫克蛋白质33.4纳摩尔。125I标记的GH与下丘脑结合的相应数字分别为每纳摩尔/升5.6和每毫克蛋白质21.6纳摩尔。通过对交联的激素-受体复合物进行十二烷基硫酸钠电泳，分别测定了脉络丛和下丘脑中结合单位的分子量为60,000和61,000。进一步表明，大鼠GH的结合单位与催乳素的不同。
