Rat brain cells in primary culture: Characterization of angiotensin II binding sites
Rat brain cells in primary culture: Characterization of angiotensin II binding sites
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原代培养中的大鼠脑细胞：血管紧张素 II 结合位点的表征
DOI：
10.1016/0006-8993(81)90369-3
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发表时间：
1981
期刊：
影响因子：
2.9
通讯作者：
R. Fellows
中科院分区：
文献类型：
--
作者：
M. Raizada;Joseph W. Yang;M. Phillips;R. Fellows
血管紧张素 II (ANG II) 的结合动力学已在胎鼠脑的原代培养物中进行了研究。 [125I]ANG II 与培养物中的大鼠脑细胞的结合具有时间、pH 和细胞浓度依赖性。结合是可饱和的、可逆的、90-95% 的特异性。结合遵循一级动力学，K1 和 K−1 的值分别为 4.9 × 106M−1S−1 和 3.33 × 104S−1。 Scatchard 分析表明存在单一类别的 Kaof 1.0 × 109M−1 结合位点，每个细胞平均约有 6 × 103 个位点。根据Sephadex G-25上的凝胶过滤和放射受体测定判断，在结合测定的条件下或从细胞解离后从培养介质中回收的[125I]ANG II没有显着降解。 ANG II 类似物与 [125I]ANG II 竞争结合，其效力总体上与先前确定的生物活性相当。在测试的 5 个类似物中，(Ile8)-ANG II 几乎与 ANG II 等价，而 (Dval3)-ANG II 在竞争性结合测定中效力最弱。这些数据满足鉴定哺乳动物脑细胞中特定血管紧张素 II 受体的标准。
The binding kinetics of angiotensin II (ANG II) have been studied in primary cultures from fetal rat brain. Binding of [125I]ANG II to rat brain cells in culture is time-, pH- and cell concentration-dependent. The binding is saturable, reversible, and 90–95% specific. Binding follows first-order kinetics, with values for K1and K−1of 4.9 × 106M−1S−1and 3.33 × 104S−1respectively. Scatchard analysis reveals the presence of a single class of binding sites with Kaof 1.0 × 109M−1and an average of approximately 6 × 103sites per cell. [125I]ANG II recovered from incubation medium under the conditions of the binding assay or after dissociation from cells is not significantly degraded as judged by gel filtration on Sephadex G-25 and radioreceptor assay. ANG II analogs compete with [125I]ANG II for binding, with potencies in general paralleling previously established biological activities. Of 5 analogs tested, (Ile8)-ANG II was almost equipotent with ANG II while (Dval3)-ANG II was least potent in the competitive binding assay. These data fulfill criteria for the identification of specific angiotensin II receptors in cells cultured from mammalian brain.