P450 metabolites of EPA and DHA, 17,18-EEQ and 19,20-EDP, respectively, induce an equivalent degree of vasodilation in the abdominal aorta and mesenteric arterioles in CYP1A1 WT and KO mice. Vasodilation in abdominal aorta to (A) 17,18-EEQ and (B) 19,20-EDP. Vasodilation in mesenteric resistance arterioles to (C) 17,18-EEQ and (D) 19,20-EDP. Data represent mean ± SEM and were analyzed by two-way, repeated measures ANOVA, using post hoc Holm-Sidak comparisons; *p < 0.05, compared to WT (n=6–8/genotype).