mRNA expression of MMP-2 and MMP-9. (a) MMP-9 gene expression is increased in the hippocampus of DSS/H rats compared with control rats. In addition, there are no differences between the DSS/H+ olmesartan and DSS/L groups. (b) No changes are observed in MMP-2 gene expression between the groups. *P < 0.01 vs. DSS/L. DSS/H, Dahl salt-sensitive/high-salt diet; DSS/L, Dahl salt-sensitive/low-salt diet; HS, high salt; MMP, metalloproteinase.