The exacerbation of cardiac and renal dysfunction in CRF–CHF, along with significant disturbances in sodium and water metabolism, as well as the abnormal upregulation of AVPR1a and AVPR2 expression levels in the renal medulla, suggests that AVPR1a and AVPR2 may be involved in regulating the abnormal sodium and water metabolism in CRF–CHF. Here, AVPR2 is linked to congestive heart failure.