Plasma TBARS levels (A) and aortic superoxide production (B). NS + HF diet–fed DSS rats showed higher plasma TBARS levels and aortic superoxide production (lucigenin chemiluminescence) than NS diet–fed DSS rats. In NS + HF diet–fed DSS rats, treatment with olmesartan, but not hydralazine, prevented the increases in plasma TBARS levels and aortic superoxide production. TBARS, thiobarbituric acid reactive substances. *P < 0.05: NS/DSS rats vs. NS + HF/DSS rats, NS + HF/DSS rats + olmesartan or NS + HF/DSS rats + hydralazine; †P < 0.05: NS + HF/DSS rats vs. NS + HF/DSS rats + olmesartan or NS + HF/DSS rats + hydralazine.