Silencing of F229V-V2R. (A) cAMP levels assessed using the CRE-luciferase reporter assay in cells expressing WT-, F229V-, R137C-, or R137L-V2R, under basal condition (vehicle) or after an 18-hour treatment with satavaptan or tolvaptan (10 μM). (B) Time-dependent changes in cAMP levels assessed using the BRET-based exchange protein directly activated by cAMP (EPAC) biosensor on cells expressing F229V- (left panel) or WT-V2R (right panel) in the presence of either vehicle, AVP (1 μM), satavaptan, or tolvaptan (10 μM each). (C) Dose-response curve of tolvaptan on cells expressing F229V-V2R using the BRET-based EPAC biosensor. Data are the mean ± SEM of three independent experiments (A and C) or representative of three independent experiments (B). *Comparison of mutant receptors with WT; #comparison of treated samples with control. *P<0.05; ***,###P<0.001.