Evidence for the presence and characterization of angiotensin II receptors in rat anterior pituitary membranes.
Evidence for the presence and characterization of angiotensin II receptors in rat anterior pituitary membranes.
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大鼠垂体前膜中血管紧张素 II 受体的存在和特征的证据。
DOI：
10.1210/endo-110-2-665
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发表时间：
1982
期刊：
影响因子：
4.8
通讯作者：
A. Negro
中科院分区：
文献类型：
--
作者：
A. Mukherjee;Padmakar V. Kulkarni;S. Mccann;A. Negro
该实验室之前的工作 (1) 表明，血管紧张素 II (AII) 可以影响体内和体外几种垂体前叶激素的释放。为了确定特定受体是否介导AII对垂体前叶的影响，分析了[125I]AII与大鼠垂体前叶膜的特异性结合以及结合动力学。 [125I]AII 的结合很快，在 37℃ 下 4 分钟内达到平衡。特异性结合约为 90%。增加配体浓度导致结合饱和，在[125I] AII = 2 nM 时达到平衡。 Scatchard 数据分析表明只有一类结合位点，平衡解离常数 Kd = 0.49 nM，最大结合能力为 40 fmol/mg 蛋白质。特异性结合与膜蛋白浓度（范围 20-240 微克蛋白质）成正比。 (Sar1, Ala8) AII (Saralasin)（一种特定的 AII 受体拮抗剂）在等摩尔基础上竞争性抑制结合。十肽血管紧张素 I 在抑制特异性 AII 结合方面的效力大约低 10-20 倍。这些研究证明并描述了垂体前叶中 AII 的特定受体位点，并为 AII 在垂体前叶激素分泌调节中的作用提供了额外的证据。
Previous work from this laboratory (1) indicates that angiotensin II (AII) can affect release of several anterior pituitary hormones, both in vivo and in vitro. To ascertain whether specific receptors mediate the effects of AII on the anterior pituitary, specific binding as well as the kinetics of [125I] AII binding to rat anterior pituitary membranes were analyzed. Binding of [125I] AII was rapid, reaching equilibrium within 4 min at 37 C. Specific binding was approximately 90%. Increasing concentrations of ligand resulted in saturation of binding, with equilibrium attained at [125I] AII = 2 nM. Scatchard analysis of the data indicated a single class of binding sites, with an equilibrium dissociation constant, Kd = 0.49 nM, and a maximum binding capacity of 40 fmol/mg protein. Specific binding was directly proportional to membrane protein concentration (range 20-240 micrograms protein). Binding was competitively inhibited on an equimolar basis by (Sar1, Ala8) AII (Saralasin), a specific AII receptor antagonist. The decapeptide Angiotensin I was about 10-20-fold less potent in inhibiting specific AII binding. These studies demonstrate and characterize specific receptor sites for AII in the anterior pituitary gland and offer additional evidence for a role of AII in the regulation of anterior pituitary hormone secretion.
血管紧张素II对雌性大鼠体内和体外垂体前叶激素释放的影响。
影响因子：
4.8
作者：
Steele,MK;Negro-Vilar,A;McCann,SM
通讯作者：
McCann,SM