Studies showed that Fuling could downregulate the expression of aquaporin 2 (AQP2) mRNA and protein, reduce the excretion of AQP2 in urine, and downregulate the expression of arginine vasopressin in plasma and expression of mRNA of vasopressin receptor 2, thereby improving urinary retention and cardiac function in rats with chronic heart failure. Here, AQP2 is linked to congestive heart failure.