In subjects with acute stroke the infusion of uric acid induced a decrease of total and active MMP-9 levels [49] and the treatment with antioxidants (polyethylene glycol-superoxide dismutase and N-acetyl-L-cysteine) reduces the MMP-9 activity in plasma and in aortic tissue homogenates of experimental models of diabetes mellitus [39] and the use of tempol (a ROS scavenger) reduces MMP-2 levels and its activity in aortic rings of animal models of renovascular hypertension [50]. Here, MMP9 is linked to renovascular hypertension.