A: body weight in Dahl salt-sensitive (SS) and SS-Rag1−/− rats fed either the normal (18%) or high (30%)-protein chow. B: steady-state sodium excretion between SS and SS-Rag1−/− rats fed either the normal (18%) or high (30%)-protein chow during low salt (0.4% NaCl) and throughout 3 wk of high salt (4.0% NaCl). Two-way repeated-measures ANOVA with Holm-Sidak post hoc test, **P < 0.001 vs. week 6. Here, 18% SS, n = 8; 30% SS, n = 7; 18% SS-Rag1−/−, n = 8; 30% SS-Rag1−/−, n = 5–7.