Role of oxidative stress in the impaired myogenic responses observed in arteries from Chow ( n = 5), HSD ( n = 5) and HFD ( n = 6) rats. Experimental vessels were exposed to the combined antioxidants tiron (10 mM) and catalase (1200 U/mL). Maximum responses at which point no further increases were seen are indicated by arrows and were determined from the two-way RM-ANOVA within group analyses. Data from untreated HSD and HFD arteries repeated from Figure 2 for comparison. #p < 0.05 from respective HSD or HFD untreated arteries at the same pressure step. Data expressed as means ± SEM.