The lack of antihypertensive effects of Tempol might be explained by the need of a fully functional system of other (non-SOD) antioxidant enzymes to drive the H2O2 generated from superoxide dismutation to CO2 and H2O. In contrast to Tempol, we found that acute administration of PEG-catalase did decrease MAP in CKD. Here, CAT is linked to chronic kidney disease.