Skorecki K L, Ballermann B J, Rennke H G, Brenner B M
Fed Proc. 1983 Nov;42(14):3064-70.
Equilibrium binding studies with angiotensin II (AII) in isolated rat renal glomeruli indicate the presence of a single population of high-affinity AII receptors. Autoradiographic studies localize these receptors to glomerular mesangial cells, which are ideally positioned to modulate glomerular capillary patency and hence the glomerular capillary ultrafiltration coefficient. Modulation of AII receptor density occurs in response to alterations of circulating AII levels, with down-regulation of receptor number in the presence of salt depletion. Kinetic studies of the ligand dissociation rate performed in the presence and absence of MgCl2 and GTP indicate multiple affinity states and suggest that this receptor is coupled to a guanyl nucleotide regulatory unit. Such coupling may provide a basis for interaction with cyclase-activating hormones in modulating the contractile state of the mesangium.
对分离的大鼠肾小球中血管紧张素II（AII）进行的平衡结合研究表明，存在单一群体的高亲和力AII受体。放射自显影研究将这些受体定位到肾小球系膜细胞，这些细胞处于理想位置，可调节肾小球毛细血管通畅度，从而调节肾小球毛细血管超滤系数。AII受体密度的调节是对循环中AII水平变化的反应，在盐缺乏时受体会下调。在有和没有MgCl2及GTP的情况下进行的配体解离速率动力学研究表明存在多种亲和力状态，并提示该受体与鸟苷酸调节单位偶联。这种偶联可能为在调节系膜收缩状态时与环化酶激活激素相互作用提供基础。
