Fig. 3.

Effects of the mutants on the inverse agonism of four ARBs in the WT-BG cells as measured by IP assay. The inverse agonist activity of Losartan (A), EXP3174 (B), Valsartan (C), and Irbesartan (D) at a concentration of 10 μM of each ARB in the COS1 cells transfected with WT-AT1 (white bars), single mutants (gray bars), and double mutants (black bars) is shown. Double mutants were constructed using two independent mutants that significantly attenuated the inverse agonist activity. Inverse agonist activity is expressed as the percentage of the constitutive activity of either WT-AT1 or each mutant. The constitutive activity of the vehicle-treated WT-AT1 cells and each mutant is defined as 0%, respectively. *P < 0.05 versus WT-AT1; †, additive effect. Gray and black bars indicate single and double mutants, respectively.