Figure 1.

Effect of SNP on the binding properties of AT₁ receptor. (a) HEK-293 cells stably expressing the AT₁ receptor (50 μg of protein) were treated with increasing concentrations of SNP for 30 min at 37°C. Broken cells were then prepared as described in Methods and incubated with 1 nM ¹²⁵I-Ang II for 1 h at room temperature as described in Methods. Nonspecific binding was assessed in the presence of 1 μM unlabeled Ang II. (b) HEK-293 cells stably expressing the AT₁ receptor (10 μg of protein) were treated (filled symbols) or not (open symbols) with 1 mM SNP for 30 min at 37°C. Broken cells were then incubated for 1 h at room temperature with increasing concentrations of ¹²⁵I-Ang II. Scatchard analysis of the data is shown in the inset. Nonspecific binding was assessed in the presence of 1 μM unlabeled Ang II. Each data represents the mean of ±s.d. of triplicate values (representative of three independent experiments).