Lixivaptan, a New Generation Diuretic, Counteracts Vasopressin-Induced Aquaporin-2 Trafficking and Function in Renal Collecting Duct Cells

• Published in: International journal of molecular sciences 2019-12, Vol.21 (1), p.183
• Main Authors: Di Mise, Annarita, Venneri, Maria, Ranieri, Marianna, Centrone, Mariangela, Pellegrini, Lorenzo, Tamma, Grazia, Valenti, Giovanna
• Format: Article
• Language: English
• Subjects: Animals; Aquaporin 2; Aquaporin 2 - genetics; Aquaporin 2 - metabolism; Benzamides - pharmacology; Body water; Cell Line; Collecting duct; Cyclic AMP; Deamino Arginine Vasopressin - adverse effects; Diuretics; Diuretics - pharmacology; FDA approval; Fluorescence; Gene Expression Regulation - drug effects; Heart failure; Hepatocytes; Hyponatremia; Kidney Tubules, Collecting - cytology; Kidney Tubules, Collecting - metabolism; Liver; Mice; Osmosis; Peptides; Permeability; Phosphorylation; Plasma; Protein kinase A; Pyrroles - pharmacology; Reabsorption; Receptors, Vasopressin - genetics; Receptors, Vasopressin - metabolism; Renal function; Retention; Signal transduction; Signal Transduction - drug effects; Vasopressin; Vasopressin V2 receptors
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms21010183

Vasopressin V2 receptor (V2R) antagonists (vaptans) are a new generation of diuretics. Compared with classical diuretics, vaptans promote the excretion of retained body water in disorders in which plasma vasopressin concentrations are inappropriately high for any given plasma osmolality. Under these conditions, an aquaretic drug would be preferable over a conventional diuretic. The clinical efficacy of vaptans is in principle due to impaired vasopressin-regulated water reabsorption via the water channel aquaporin-2 (AQP2). Here, the effect of lixivaptan-a novel selective V2R antagonist-on the vasopressin-cAMP/PKA signaling cascade was investigated in mouse renal collecting duct cells expressing AQP2 (MCD4) and the human V2R. Compared to tolvaptan-a selective V2R antagonist indicated for the treatment of clinically significant hypervolemic and euvolemic hyponatremia-lixivaptan has been predicted to be less likely to cause liver injury. In MCD4 cells, clinically relevant concentrations of lixivaptan (100 nM for 1 h) prevented dDAVP-induced increase of cytosolic cAMP levels and AQP2 phosphorylation at ser-256. Consistent with this finding, real-time fluorescence kinetic measurements demonstrated that lixivaptan prevented dDAVP-induced increase in osmotic water permeability. These data represent the first detailed demonstration of the central role of AQP2 blockade in the aquaretic effect of lixivaptan and suggest that lixivaptan has the potential to become a safe and effective therapy for the treatment of disorders characterized by high plasma vasopressin concentrations and water retention.