Deficient adaptive response to low Na⁺ intake in sgk1^–/– mice. (a) Urinary excretion of Na⁺ and water, and change in body weight in response to a low-NaCl diet (0 g Na⁺/kg) assessed in awake mice in metabolic cages (n = 6 each group). (b) Shown are mean arterial blood pressure and GFR in anesthetized mice on the control diet and at day 3 after initiating the low-NaCl diet (0.15 g Na⁺/kg) (n = 5–6 each group); and plasma aldosterone concentration in mice on control diet and at day 3 after initiating low-NaCl diet (0 g Na⁺/kg) (n = 8–9 each group). Filled circles and bars indicate sgk1^–/– mice, open circles and bars indicate sgk1^+/+ mice. *P < 0.05 versus sgk1^+/+ mice.