AVP and heart failure: Therefore, using a postmyocardial infarction heart failure model, the present study was carried out to determine (1) whether QL can reduce volume overload and improve cardiac function in the late phase of infarction, (2) whether AQP2 and pS256-AQP2 are involved in the effects of QL, and (3) whether QL can regulate AVP-V2R-AQP2 and AngII-AT1R-AQP2 signaling in the renal medulla.