The medullary expression of V2R was down‐regulated (0.56‐fold) and the expression of NHERF‐1 (denoted by Slc9a3r1, a gene which tended to decrease in CHF rats, threefold up‐regulation) was increased in response to RGZ treatment (P < 0.05 for both, Table 2 and 3, Figure 8). Here, AVPR2 is linked to congestive heart failure.