Azilsartan Medoxomil (TAK-491) is an orally administered angiotensin II receptor type 1 antagonist with IC50 of 0.62 nM, which used in the treatment of adults with essential hypertension.

Ang II type 1 receptor:0.62 nM

Azilsartan medoxomil 是一种前药，在口服摄入后，通过肠道和血浆中的酯类水解迅速转化为活性物质 Azilsartan (TAK-536)。Azilsartan 选择性地阻断血管平滑肌和肾上腺发现的 AT1 (angiotensin II type 1) 受体与血管紧张素 II 的结合，从而促进血管舒张和降低Dicirenone 的效应。[2] Azilsartan 是 AT1 受体的高选择性拮抗剂，其 IC50 值为 2.6 nM，与 AT2 受体相比具有超过 10,000 倍的亲和力，且未显示对其他心脏受器或离子通道的亲和力。即使洗脱了自由化合物后，Azilsartan 的抑制效果仍持续存在（IC50 值为 7.4 nM）。此外，Azilsartan 还能抑制血管紧张素 II 诱导的肌醇 1-磷酸（IP1）在细胞测定中的积累，其 IC50 值为 9.2 nM，且该效应具有耐洗脱性（IC50 值为 81.3 nM）。[1]

Radioligand Binding: A radioligand binding assay is performed by using human AT1 receptor-coated microplates containing 4.4 to 6.2 fmol of receptors/well (10 μg of membrane protein/well). Membrane-coated wells are incubated with 45 μl of assay buffer (50 mM Tris-HCl, 5 mM MgCl2, 1 mM EDTA, and 0.005% CHAPS, pH 7.4) containing various concentrations of test compounds at room temperature. After 90 min, 5 μl of 125I-Sar1-Ile8-AII (final concentration 0.6 nM) dissolved in assay buffer is added to the wells, and the plate is incubated for 5 h. In each step, the plate is briefly and gently shaken on a plate shaker.

Measurement of Inositol 1-Phosphate Accumulation. Twentyfour hours after transfections with human AT1-expressing plasmids, the cells are starved by changing the culture medium to starvation buffer (1 mM CaCl2, 0.5 mM MgCl2, 4.2 mM KCl, 146 mM NaCl, 5.5 mM glucose, and 10 mM HEPES, pH 7.3). Then, 5 μl/well of the test compounds dissolved in starvation buffer is added to the cells at the indicated concentrations, and they are pretreated for the indicated times. Two hours after starvation, LiCl is added to a final concentration of 50 mM with or without angiotensin II 10 nM, and the cells are further incubated for the indicated times at 37°C. In washout experiments, the cells are washed once with 100 μl/well of starvation buffer to remove unbound compounds before stimulation with angiotensin II. The accumulation of inositol 1-phosphate (IP1) is measured by using a IP-One Tb kit. The fluorescence resonance energy transfer signal is measured on a plate reader.(Only for Reference)