PHARMACOLOGICAL CHARACTERIZATION OF 2 SPECIFIC BINDING-SITES FOR NEUROHYPOPHYSEAL HORMONES IN HIPPOCAMPAL SYNAPTIC PLASMA-MEMBRANES OF THE RAT
PHARMACOLOGICAL CHARACTERIZATION OF 2 SPECIFIC BINDING-SITES FOR NEUROHYPOPHYSEAL HORMONES IN HIPPOCAMPAL SYNAPTIC PLASMA-MEMBRANES OF THE RAT
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DOI：
10.1002/j.1460-2075.1985.tb03794.x
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发表时间：
1985-01-01
期刊：
影响因子：
11.4
通讯作者：
BARBERIS, C
中科院分区：
文献类型：
--
作者：
AUDIGIER, S;BARBERIS, C
从大鼠海马中分离出含有氚标记催产素和精氨酸加压素结合位点的突触质膜。测定催产素和加压素位点的结合参数并进行统计学分析。催产素结合的拟合曲线与配体与具有不同容量和亲和力的2类受体相互作用的模型相容。具有低结合能力的位点在平衡时具有1.8 nM的表观Kd和17 fmol/mg蛋白质的最大结合能力。相比之下，Scatchard图未能揭示标记有[3 H]加压素的位点群体中的显著异质性，其亲和力为1.5 nM，最大结合容量为39 fmol/mg蛋白质。这些结合位点的特异性，在竞争实验中测试，揭示了这些神经垂体激素标记2个不同的群体的网站。一个群体对后叶加压素、催产素和催产素具有高亲和力，另一个群体对后叶加压素和催产素具有高亲和力，而对催产素具有低亲和力。腺苷酸环化酶活性不受精氨酸加压素或催产素的影响。这些受体与以前表征的外周受体进行了比较。
Synaptic plasma membranes containing binding sites for tritiated oxytocin and arginine vasopressin were isolated from rat hippocampus. The binding parameters for oxytocin and vasopressin sites were determined and statistically analyzed. The fitted curve for oxytocin binding was compatible with a model where the ligand interacts with 2 classes of receptors with different capacities and affinities. The sites with low binding capacity had an apparent Kd at equilibrium of 1.8 nM and a maximal binding capacity of 17 fmol/mg protein. By contrast, the Scatchard plot failed to reveal a marked heterogeneity in the population of sites labeled with [3H]vasopressin with an affinity of 1.5 nM and a maximal binding capacity of 39 fmol/mg protein. The specificity of these binding sites, tested in competition experiments, revealed that these neurohypophyseal hormones labeled 2 distinct populations of sites. One population with a high affinity for vasopressin, oxytocin and vasotocin, the other population with a high affinity for vasopressin and vasotocin and a low affinity for oxytocin. Adenyalate cyclase activity was not affected by arginine-vasopressin or oxytocin. These receptors are compared with previously characterized peripheral receptors.