ARG1 and diabetes mellitus: The major findings of this study are that (1) diabetic Arg1‐KOTie2 mice have a higher arginine concentration in plasma, (2) hemodynamics are not affected by endothelial ARG1 ablation, (3) vasomotor function is not affected by endothelial ARG1 deficiency in normoglycemic mice, and (4) diabetes‐induced alterations in arterial smooth muscle reactivity and endothelium‐dependent relaxations are not prevented by endothelial ARG1 ablation.