A: representative light microscopy images of trichrome-stained kidneys after 3 wk of high-salt challenge in Dahl salt-sensitive (SS) and SS-Rag1−/− rats fed either the normal (18%) or high (30%)-protein chow (×4), with the quantification of the percentage of outer medullary protein casts summarized in B. C: light microscopy images of representative glomeruli (×40) from kidneys obtained from SS and SS-Rag1−/− rats after 4.0% NaCl normal protein or high-protein diet, with the percentage of damaged glomeruli summarized in D. Two-way ANOVA with Holm-Sidak post hoc test, **P < 0.001 vs. 18% SS, ##P < 0.001 vs. 30% SS. Here, 18% SS, n = 8; 30% SS, n = 7; 18% SS-Rag1−/−, n = 8; 30% SS-Rag1−/−, n = 6.