Figure 4

Claudin-2 expressions in the kidney cortex of rats fed 0.3% or 8% NaCl for 8 weeks. Protein and mRNA were normalized against GAPDH expression and expressed as relative amounts. Salt loading for 8 weeks increased the expression of claudin-2 mRNA (4A), but significantly decreased its protein level (4B). * P <0.05 vs 0.3% NaCl group, n=14-16. Claudin 2 immunnohistochemistry in kidney from rat on normal-salt diet (4C), high-salt diet (4D), and no primary antibody control (4E). Arrowheads indicate claudin 2 staining. By subjective observation, normal-salt fed rat kidney (4C) shows more claudin 2 staining compared to salt-loaded rat kidney (4D).