Rats were fed a CD or WTD for 13 weeks, treated with vehicle or CDDO-Me for 2 weeks and administered saline or glucose for 1 week. A: Curves of endothelium-dependent relaxation in response to ACh under 5.5 mM glucose or 20 mM glucose conditions. † P < 0.01 and ‡ P < 0.005 compared with the other three groups, one-way repeated-measures ANOVA with the Bonferroni post hoc test. B: Vascular sensitivity, plotted as pD2 (- log of the half-maximal effective concentration [EC50]) of ACh. § P < 0.001, one-way ANOVA with the Bonferroni post hoc test. The data are presented as the means ± SEM. N = 4 rats per group. Glu, glucose; ACh, acetylcholine; CD, control diet; WTD, Western-type diet; GS, glucose spike.