大鼠脑神经生长因子受体分布的实验研究

本文报道了一种测定脑内神经生长因子（ＮＧＦ）受体的竞争性结合分析法。应用１２５Ｉ－ＮＧＦ作为放射配基，在含有过量未标记ＮＧＦ条件下，１２５Ｉ－ＮＧＦ与不同脑组织细胞膜于３７℃下孵育３０ｍｉｎ达到可逆的平衡状态的。Ｓｃａｔｃｈａｒｄ分析，根据其与配体亲和力的不同分为高亲和力（Ⅰ型）与低亲和力（Ⅱ型）结合位点两种受体亚型，平衡解离常数（Ｋｄ）分别约为４ｐｍｏｌＬ－１及１．６ｎｍｏｌＬ－１，最大结合能力（Ｂｍａｘ）约为０．５ｆｍｏｌ／Ｌｍｇ－１（蛋白）及２４ｆｍｏｌ／Ｌｍｇ－１（蛋白）。脑内各分区ＮＧＦ受体的结合容量依次为中隔、小脑、脑干、大脑皮质、下丘脑、嗅脑。

Research on distribution of nerve growth factor in rat brain

A competitive binding assay of nerve growth factor (NGF) receptor was described using 125 I-NGF as the radioligand.The binding of 125 I-NGF to cell membranes of brain reached reversible equilibrium within 30 min at 37℃ under the condition of an excess of unlabled NGF.Scatchard analysis of the date revealed that two classes of binding sites could be detected with an apparent Kd of 4 pmol·L -1 and a maximal binding capacity of 0.5 fmol/L·mg -1 (protein) for the high affinity binding site and Kd of 1.6 nmol·L -1 with a maximal binding capacity of 24 fmol/L·mg -1 of (protein) for the low affinity binding site.The receptor concentrations in turn are middle septal,cerebullum,brain stem,hippocampus,cerebral cortex,thalamus and olfactory brain.