AT1AAVP-KO mice exhibit altered fluid homeostasis. A: serum osmolality (control: male n = 24, female n = 9; AT1AAVP-KO: male n = 16, female n = 3) at baseline. B–E: measures of body fluid status, including fluid mass (B; control: male n = 9, female n = 9; AT1AAVP-KO: male n = 3, female n = 2), hematocrit (C; control: male n = 8, female n = 6, AT1AAVP-KO: male n = 5, female n = 2), water intake (D; control: male n = 9, female n = 9; AT1AAVP-KO: male n = 13, female n = 9), and urine production (E: control: male n = 9, female n = 9; AT1AAVP-KO: male n = 13, female n = 9). F: plasma copeptin (control: male n = 7; female n = 11; AT1AAVP-KO: male n = 4, female n = 4) at baseline. Data are expressed as means ± SE. *P < 0.05, between genotypes.